Cadillac's all-new sedan STS is designed and engineered to be one of the finest luxury sedans available, with the added benefit of Cadillac's distinctive modern styling. The largest car to be based on GM's acclaimed rear-wheel-drive Sigma architecture offers the choice of 3.6-liter V6 VVT or 4.6-litre Northstar V8 engines. STS is the product of unwavering attention to detail, resulting in excellent fit and finish, refined performance, overall harmony and purposeful innovation.
Overview
From its Cadillac-signature styling to its performance capabilities, there's no mistaking the STS as anything but a contemporary Cadillac. Signature items styling include vertically stacked headlamps and light-emitting diode (LED) tail lamps, LED center high-mounted stop light (CHMSL), horizontal "spline lines" and dihedral-shaped hood.
With an overall length of 4985 mm, a wheelbase of 2957 mm and front/rear track of 1596/1581 mm the STS is the largest sedan in the GM Sigma-based family, which is also the foundation for Cadillac's entry-luxury CTS sedan, CTS V-series high-performance sedan and SRX luxury performance crossover. This ensures a particularly spacious and stylish interior, with an emphasis on high-quality fit and finish.
Premium quality materials are used throughout. Eucalyptus wood and aluminium trim appears on the steering wheel, center console, instrument panel and door armrests. Dual-firmness leather seats are specially tanned for a softer feel, with the added option of Tuscany leather upholstery. Natural grained surfaces on the door and instrument panel ensure an inviting, tactile touch, as do the headliner and interior pillars, which are soft backed and covered with a Monaco woven fabric.
The STS is offered with the 189 kW (257 horsepower) 3.6L V-6 VVT or the 239 kW (325 hp) Northstar 4.6L V-8. Both engines incorporate variable valve timing (VVT) and are mated to Cadillac's widely acclaimed five-speed automatic transmissions with Driver Shift Control. The 4.6L Northstar engine delivers 0-100 km/h acceleration in 6,2 seconds. With the V-6 the STS will achieve 0-100 km/h in 7,4 seconds.
Four-cam variable valve timing gives the V6 engine increased efficiency, with benefits in fuel economy, reduced emissions and a wide-ranging flexibility. 90 percent of the 3.6L V-6's peak torque is available across a broad operating range: from 1600 rpm to 5800 rpm. In addition, an electronically controlled throttle (ETC) effectively coordinates the driver's intentions with the actions of the various control components.
Real time damping
Integrated chassis control technologies combine high dynamic performance with a comfortable ride, including two-mode Magnetic Ride Control with performance or touring selections as standard on the V8. The electronically controlled magnetic-fluid based real time damping used on STS is the world's fastest-reacting suspension control system. Driver involvement is further enhanced by high-precision ZF steering gear and four-channel StabiliTrak which assists the vehicle in maintaining the driver's intended path by applying a brake force at any corner of the vehicle independent of the driver's use of the brake pedal. StabiliTrak is fully integrated with the traction control and ABS systems.
Plentiful, purposeful and driver oriented technical appointments include a Keyless Access system with a push button start; optional Adaptive Cruise Control (ACC) and reconfigurable four-color head-up display (HUD); heated and ventilated seats and heated steering wheel. The STS Elegance model comes highly specified as standard, with eight-way power seat adjustments for the driver and front occupant including a memory package which provides presets for two drivers and automatically adjusts the outside rear-view mirrors; power tilt and telescoping steering wheel position, radio and climate control settings.
Additional refinements on the special Launch Edition include the Eucalyptus wood trim package, heated front and rear seats, heated steering wheel, power lumbar adjustment on the front seats and an uplevel infotainment system, with a 15 speaker Bose 5.1 Surround Sound system with an integrated six-disc CD/DVD changer, an 8-inch (203 mm) VGA quality touch screen, Bluetooth capability, advanced voice recognition and an advanced navigation system.
Early in 2006, a high-performance Cadillac STS-V will also join the model line-up. This features a 4.4-liter DOHC Northstar V-8 SC engine with a positive displacement intercooled supercharger, the first supercharger ever on a production Cadillac delivering the highest horsepower rating of any production Cadillac engine to date.
The Cadillac STS is being built alongside its CTS, CTS-V and SRX stablemates at GM's state-of-the-art Lansing Grand River assembly center in Michigan. The facility recently received a J.D Power Gold Plant Award and was ranked the best assembly plant in North and South America in the 2004 J.D Power Initial Quality Study, in which Cadillac was voted number one amongst the toughest global luxury competition.
A distinctively bold offering of luxury and style
From its Cadillac-signature bold exterior styling to its inviting and carefully crafted interior, the STS is the product of unwavering attention to detail. More than 1,000 criteria points were strictly adhered to throughout development of the vehicle. The result combines a distinctive style with space, outstanding fit and finish, overall harmony, and purposeful innovation.
At first glance, there's no mistaking the STS as a contemporary Cadillac, with its vertically stacked headlamps and light-emitting diode (LED) tail lamps, signature LED CHMSL, horizontal spline lines, and dihedral-shaped hood. The STS carries this distinctive design vocabulary, heritage cues and styling characteristics found throughout the Cadillac product portfolio in a manner that is refined and sophisticated. It is intentionally crafted to meet the discriminating tastes of the performance luxury segment in which it competes - for the most discerning buyers in the automobile marketplace.
The overall shape lends a faster profile and more rake than its CTS sibling, but it's done so in the context of elegance and grace. Its doors-into-roof construction enables more tumblehome, the vehicle sides are sculpted inward, delivering a look of upscale rear-wheel-drive performance with a lower roof line, while maintaining a roomy interior. In addition, a wider tapering sail panel; lower, more sculptured hood; smoother wheel openings; and a tighter wheel-to-body relationship further communicate the agility of the STS, as well as sophistication and substance.
A wheelbase of 2957 cm and front/rear track of 1596/1581 mm, combined with a flush wheel-to-body relationship, ensures well-grounded appeal and presence. Overall, the STS is 4985 mm long, 1843 mm wide and 1464 mm high, making it the largest sedan offering in the GM Sigma-based family. As a result, the STS delivers ample interior space for front and rear passengers alike.
Luxury performance competence
Seven-spoke 17- or available nine-spoke 18-inch wheels and visible high-performance brake calipers and rotors leave no doubt about the STS' luxury performance competence. A wire mesh, electro-polished stainless steel lower grille reiterates the statement.
The rocker treatments on the vehicle are specific to the STS, bringing a more sculpted shape to the vehicle's lower line for more presence and refinement. A single-piece fascia design, which eliminates seams for a clean, uninterrupted appearance, enables excellent fit and finish. Vertically stacked headlamps, a traditional Cadillac cue, are slightly narrower and lower than seen on other Cadillac models. The headlamps incorporate large, dual 70-millimeter projector lenses encased in an aluminized, single piece bezel.
LED tail lamps are designed with indirect optics, an industry-first application, and incorporate 30 sources of illumination per unit. The use of indirect optics eliminates "pinpoints" of light normally associated with LEDs and enables an upscale, refined appearance when illuminated. On the STS, each tail lamp has two vertical arrays consisting of 15 LEDs, with each LED containing 20 optical facets. This configuration enables very precise illumination tuning and the design flexibility needed to meet both US domestic and export requirements.
The LED CHMSL on the STS is only 12-millimeters thick and consists of 78 points of illumination. An ingenious lens design incorporates the use of pillow optics, which again replaces a "pinpoint" appearance normally associated with LEDs with a smooth, refined output of light.
Single piece front fascia design
An integrated, precision-molded front fascia is constructed of thermal plastic olefin (TPO). Its single-piece design eliminates seams, and delivers outstanding dimensional execution to mating surfaces. The fascia incorporates upper and lower grilles and openings for headlamps, park/turn lamps, fog lamps and front side markers. In addition, HID headlamp washer elements are mounted flush to the fascia's surface for a smooth, clean appearance.
The rear styling of the STS is clean and uninterrupted, due in large part to a one-piece superplastic-formed aluminium decklid, with an integrated pocket on the trailing edge for the LED CHMSL. Use of the superplastic forming process has enabled integration of rear lighting elements without use of additional appliqués or trim. Styling lines, exhaust cut-outs, rear valance, rear fog lamps and the rear parking assist sensors are cleanly integrated into the overall design.
The styling of the STS is complemented by a wide range of exterior paint colors. These are: Blue Chip, Red Line, Black Raven, Silver Smoke, Sand Storm, Moonstone, Light Platinum, White Diamond and Silver Green Metallic.
Finely crafted, inviting interior
The interior of the STS is executed to extremely close and demanding tolerances, enabling a tight, well-crafted appearance throughout. Premium materials and surfaces are found throughout the interior. In-mould processed aluminium, which is particularly dent and mark resistant, is used for trim highlights on the Elegance model, with the Launch Edition offering Eucalyptus wood on the steering wheel, center console, instrument panel, and door armrests. A heated, leather-wrapped steering wheel is optionally available. Natural grained surfaces on the door and instrument panel ensure an inviting tactile touch, as do the headliner and interior pillars, which are soft backed and covered with a Monaco woven fabric.
The STS features dual-firmness seats (optionally available as heated and ventilated) that are specially tanned for a softer feel. The seat design's optimized dual-firmness strategy uses a pillow-like upper padding combined with a firmer seat cushion to achieve luxurious comfort as well as outstanding support. The standard Nuance leather seating surfaces or available Tuscany leather seats are available in Light Gray, Ebony or Cashmere finishes.
Eight-way seat adjustment
Power seat adjustments for the driver and front occupant provide eight-way seat adjustment with a memory package providing presets for two drivers, including settings for eight-way power driver/passenger seats with an easy exit driver seat; outside rear-view mirrors; power tilt and telescoping steering wheel position, radio and climate control settings. Four-way power lumbar adjustment and articulating head restraints are available on the Launch Edition.
The STS features analogue instrumentation, defined by bright accents and includes speedometer, tachometer, fuel gauge and engine water temperature. The Driver Information Center (DIC) is displayed in the gauge cluster, and has six-language capability (English, French, German, Italian, Japanese and Spanish). A standard electrochromic (light-sensitive auto dimming) interior rearview mirror is integrated with the interior.
Body, safety and security
From the inner structure to the architecture of the exterior sheet metal, the all-new Cadillac STS has been meticulously crafted to ensure delivery of the attributes expected of a luxury sedan. The STS features a body frame integral (BFI) structure, based on the premium GM Sigma rear-wheel-drive architecture. With a BFI structure, the upper body structure and sub-frames are engineered as a single unit, enabling a mass efficient, yet stiff, body structure.
BFI structures bring an ideal foundation for achieving sports sedan performance, resulting in a particularly rigid base structure with a beaming frequency of approximately 25 Hertz and significant torsional stiffness, some 13 percent greater even than the highly competitive Cadillac CTS. This provides a strong basis for the STS to combine great chassis dynamics with high levels of refinement. Additionally STS is equipped with a host of refinements to ensure a quiet ride and interior environment and impressive wind noise performance.
The Cadillac STS joins the CTS and SRX as the first vehicles in GM to be outfitted with a laminated front-of-dash panel - a key to reducing the transfer of engine compartment noise into the cabin. Also called "quiet steel", the application is found on all Sigma architecture-based vehicles.
Noise-damping 'blanket'
The front-of-dash panel consists of two thin pieces of steel held together by composite adhesive. A sophisticated bonding process ensures the steel will not resonate noise, and damps noise transfer significantly when compared to conventional applications. A front-of-dash mat constructed of a 28-millimeter thick thermal plastic olefin (TPO) cast foam material also reduces powertrain noise transfer into the cabin. The mat, essentially a noise-damping blanket on the engine side of the dash panel, is applied with a glove-like fit and closes out all cavities in the panel.
All chassis-to-body structure interfaces (i.e., suspension brackets or cradle attachments) on the STS have been designed to improve stiffness and structure, thus further isolating low-frequency noise from the cabin. Each of the interfaces has essentially been "tuned" through shape or material thickness to ensure a robust, stiff structure that effectively minimizes vibrations and related transfer of noise from road irregularities, engine, prop shaft, and other inputs.
In order to add greater reinforcement to the center tunnel of the STS, which serves as the "backbone" of the vehicle, a tubular structured U-shaped "strap" was added for tension and compression, again further improving the vehicle's overall stiffness. It also helps reduce vibration to the floor pan and rear seats. A constraint layer also is implemented into the tunnel structure - inner and outer steel structures are mated together in a sandwich form. As a result, the two pieces of steel dampen each other, reducing the transfer of noise and vibration into the cockpit.
Reducing noise level
To attenuate noise transfer from the shock towers into the passenger compartment, all shock towers are applied with a constraint layer, two pieces of metal that sandwich a rubber viscous material, making up the structure of each shock tower. This application again significantly reduces the noise level in the passenger compartment. Similarly both rear wheelhouses on the STS are constructed of sandwiched steel structures that mate together as inner and outer structures, dampening each other, greatly reducing the resonation of noise into the rear passenger compartment.
A front tunnel barrier is applied under the carpet on the STS to ensure superior isolation from driveline acoustics. The barrier, which runs from the dash panel rearward on either side of the tunnel where it meets the floor, is constructed of a lightweight composite with outstanding noise damping characteristics.
An acoustic laminated windshield is a key enabler of the Cadillac STS model's wind noise performance. While the windshield itself is thinner than traditional applications to reduce mass, a four-layer construction allows it to deliver the acoustic performance of thicker glass. Two layers of glass sandwich a safety laminate and an acoustical-grade vinyl sheet laminate, enabling a marked reduction in wind noise. Laminated front side glass also provides significant improvements in wind and external noise performance.
Further, typically Cadillac, attention to detail is demonstrated by the use of lightweight damping material throughout the vehicle cabin to address the high- and mid-range frequencies normally requiring heavier deadening materials. The material is a foil/rubber acoustical damping compound that is adhesively applied to the inner sheet metal, a first-time Sigma architecture application, while low weight, high-absorption trunk acoustics effectively damp noise and vibration from the luggage compartment.
Lower profile, structure-less windshield wipers deliver a wind noise reduction when compared with conventional applications. Sometimes called "flat blades", the wipers replace an arm structure, a common source of noise when wind travels through and around it, with a flexible airfoil surface that runs along the top of the blade. The airfoil is "tuned" to the shape of the windshield, ensuring a lower profile and superior contact with the windshield at all positions.
The doors-into-roof construction on the STS eliminates the need for molding along the top of side window glass and ensures consistent surfaces around the elements. This door execution, inspired by high-performance aircraft, enables extremely tight gap tolerances, removes a source of wind noise and plays a primary role in the integrated, clean and sleek appearance of the STS. A triple seal architecture around all four doors reduces vehicle interior noise levels. Three seal sets work together to effectively seal the passenger compartment from wind, water, and other elements.
Sculpted surface
The aluminium decklid on the STS luggage compartment is a complex shaped form produced using an advanced superplastic forming (SPF) process, an execution that enables a sculpted surface and outstanding dimensional accuracy. A traditional stamping execution of either steel or aluminium would have resulted in a two-piece execution of the decklid, requiring the use of additional exterior trim.
In the superplastic forming process, aluminium is heated to a state of plasticity then formed into a die cavity using air pressure. The final result is a single-piece form, with an integrated pocket for the light emitting diode (LED) CHMSL as well as the backup lamps, which ensures a clean surface throughout the contoured shape of the decklid.
The STS maintains Cadillac's long-standing reputation for delivering a safe occupant environment in premium vehicles. Structural enhancements contributing to the excellent crash performance capability of the STS include a two-piece magnesium cross-vehicle structure for side and front crash protection, octagonal engine rails to enhance high-speed offset crash protection and a one-piece hydroformed A-pillar/roof rail structure that brings added upper structural rigidity and enhanced strength during side and frontal impacts.
Inner and outer rocker panels are constructed of strong, ultra-high strength steel and longitudinal rails are injected with structural foam to protect and maintain their geometry during an impact. The foam adds to overall body structure stiffness and contributes to preventing intrusion around occupants' feet during high-speed offset impacts. Rear rail inner sections are constructed of high-strength dual phase steel - a first-time application on the Sigma architecture. Dual phase steel brings outstanding characteristics for supporting crashworthiness deformation.
Six airbags as standard
The STS has a total of six airbags offered as standard equipment, which help to maximize protection in high-speed crashes while minimizing the risk of injury to out-of-position occupants. Airbags include a dual stage driver's front airbag and a front passenger airbag, driver's and front passenger seat-mounted airbags for thorax protection, along with roof rail side curtain airbags giving head protection with front and second row coverage.
In the case of the dual-stage airbags, when the air-bag system's central control unit, the Sensing Diagnostic Module (SDM), detects an impact, it determines whether the crash is severe enough to trigger a deployment, and whether the primary amount of inflation is sufficient or if both primary and secondary stage inflation is required. The primary stage alone will deploy in most frontal impacts requiring the supplemental protection of an airbag, while the secondary stage also will deploy in very severe frontal collisions.
The SDM also detects side impacts and determines whether the rail-curtain and side seat-mounted (thorax protection) air bags should deploy. These air bags act like a protective curtain, unfolding from the roof rail between the A and C pillars. When the bag deploys, it is biased toward the window to help maximize protection.
The SDM also activates the safety belt pretensioner, which reduces slack in the safety belt webbing. This helps secure occupants in the seat to better hold them in position so they decelerate at the same rate as the car. The safety belts are equipped with 'frictionless' D-rings and low-effort retractors so there is minimum pressure on the occupant, making them more comfortable to wear. The retractors also are energy absorbing.
Second row seats have three-point safety belts in all positions. The second-row seats of the STS come equipped with the LATCH system to simplify child seat installation. These anchors, which are secured to the body structure, are provided in all three rear-seat positions.
Occupant security features
Occupant security is provided with a number of standard and available features, including child security door locks so a parent can choose to prevent their child from opening the rear doors from the inside and a power window lockout so control of the windows can be limited to the driver controls. An engine immobilizer and theft deterrent system is standard as is delayed entry lighting, which keeps the interior lights on after the driver enters and until the vehicle is started.
The Standard Remote Keyless Entry also includes a panic button on the key fob, which turns on all the lights except the headlamps, sounds the horn and activates content theft deterrent and anti-lockout features. Battery rundown protection automatically shuts off any electrical system inadvertently left on after a period of time before the battery runs down. A child entrapment release lever is fitted in the trunk and further peace of mind is offered with the option of a tire pressure monitoring system.
Chassis: a perfect balance of ride and handling
A host of chassis refinements ensure that the STS hits the perfect balance of smooth ride and entertaining handling. Road impacts and other harsh inputs are effectively absorbed and dissipated through ride-tuned tires, dampers, suspension components and bushings, as well as improved structure in body-to-chassis interfaces and additional refinements in the engine mounts. The result is a ride that keeps drivers fresh and comfortable without sacrificing the driving experience.
Among the many refinements found in the front suspension components is the use of aluminium for both the upper and lower control arms, suspension joints and brake callipers. This reduces unsprung mass, requiring less damping and dynamic wheel control, contributing to more nimble handling and better road-holding ability. Hydraulic control arm front bushings are used to provide optimum motion control while minimizing high-speed road vibration, by damping energy transmitted to the vehicle structure. A hollow front stabilizer bar on all models brings weight savings and added stability. The fully independent multilink rear suspension with fully isolated sub frame is an uncompromising design with excellent suspension kinematics that enables outstanding ride and handling performance.
At the same time, the other features of the suspension architecture give it the ability to control loads and maintain stability during dynamic driving situations, striking a balance between ride quality and high-performance handling capability. Other rear suspension features include weight-saving aluminium upper control arms, knuckles and brake callipers, along with hollow rear stabilizer bars. The rear suspension is fully isolated to reduce road and driveline noise.
Rear damping is provided by Nivomat load-levelling shocks, a fully automatic hydraulic level-regulating system with integrated shock absorber, adapt automatically to different loads and road conditions.
Front shock absorbers on base models are monotube dampers from Sachs, a leading German producer of high-performance shock absorbers, which provide highly responsive damping of road inputs.
The STS V8 model also offers as standard the award-winning Magnetic Ride Control (MR) system which uses electronic control of damping forces in a continuously variable real-time damping system to provide exceptional responsiveness, greatly increased driver control and increased tire contact with the road, regardless of road surface.
The MR system uses valveless damping and magneto-rheological (MR) fluid technology. The fluid is a suspension of iron particles in a synthetic hydrocarbon-base fluid. When the system is activated, the particles are magnetized and aligned into fibrous structures, changing the flow resistance of the fluid. By controlling the current to an electromagnetic coil inside the piston of the damper, the system varies the fluid viscosity continuously in response to road surface conditions over a broad damping range.
Increased wheel contact
Damping levels are adjusted up to 1,000 times per second, making the system exceptionally responsive and providing increased wheel contact on even the roughest road. Reduced wheel bounce ensures an even ride by virtually eliminating heave, pitch and roll. It also delivers excellent roll control during transient steering and evasive manoeuvres.
A set of wheel-to-body sensors detects changes in the road surface and the system controller adjusts the fluid viscosity to vary the damping force accordingly, providing a flatter ride during cornering and reduced diving or squatting during braking and acceleration.
The MR system on the STS is among the first to make available two selectable settings accessed through the infotainment display head - performance or touring modes. The performance mode may be used where road conditions or personal preference demand more control; the setting provides more "feel" or responsiveness to road conditions. The touring mode is available for normal city and highway driving and provides a smoother, more accommodating ride.
Enhanced steering input is offered by optional ZF Servotronic II rack-and-pinion speed-sensitive steering gear with 18.2:1 variable ratio and speed-sensitive variable assist. The turning radius of the Cadillac STS is just 11.5 meters. The standard StabiliTrak system on the STS is a sophisticated four-channel (independent control to all four corners of the vehicle) active handling system. It links the vehicle's dynamic control systems to assist the driver in maintaining control under demanding or adverse conditions such as wet, snow-covered or icy roads, tight turns, and evasive manoeuvres.
The STS is equipped with four-wheel-vented disc brakes with standard four-wheel antilock braking system (ABS) and traction control system (TCS). The brakes feature vented rotors consistent with the demands of a luxury performance sedan. Base brake package rotor dimensions are 303 x 32 mm front and 298 x 26 mm rear. Uplevel brake package rotor dimensions measure 323 x 32 mm front and 320 x 26 mm rear.
Panic Brake Assist (PBA), which senses emergency braking by detecting the speed or force the driver applies to the brake pedal and boosts the power as needed, is incorporated into the brake system. Under certain conditions, the panic brake assist may activate the ABS more quickly and easily than vehicles without the feature, potentially reducing overall stopping distance by eliminating the delay caused by not braking hard enough and/or soon enough. The system also features Dynamic Rear Brake Proportioning, which regulates braking pressure to optimize stopping distances and control under all vehicle-loading conditions.
The Cadillac STS is available with 17- or 18-inch wheels. V6 models use 17 x 7.5 cast aluminium front wheels with P235/50R17 tires and 17 x 8.0 rear wheels with P255/45R17 tires. Cadillac STS V8 models feature
18 x 8.5-inch flow-formed aluminium wheels with high performance 255/45R18 tires on all four corners.
Powertrain: refined power with wide-ranging flexibility
The new Cadillac STS is offered with two world-class powertrains. The 3.6L V-6 VVT develops 189 kW (257 horsepower) and 342 Nm of torque and the 4.6L Northstar V-8 develops 239 kW (325 hp) with 427 Nm of torque. The V-6 and V-8 power units are both mated to electronically controlled five-speed automatic transmissions - the Hydra-Matic 5L40-E is mated with the V-6, and the Hydra-Matic 5L50-E is designed to handle the V-8's increased torque. The 4.6-liter Northstar accelerates from 0-to-100 km/h in 6.2 seconds. With the V-6 the STS achieves 0-100 km/h acceleration in 7.4 seconds.
The 60-degree 3.6-liter V-6 is a highly refined, DOHC four-valves-per-cylinder engine with all-aluminium construction. The adoption of fully variable valve timing for both intake and exhaust valves provides outstanding fuel economy, emissions reduction and a wide-ranging flexibility. 90 Percent of the 3.6L V-6's peak torque is available across a remarkably broad operating range: from 1,600 rpm to 5,800 rpm. In addition, an electronically controlled throttle (ETC) effectively coordinates the driver's intentions with the actions of the various control components.
Numerous design features were incorporated into the 3.6-liter engine to ensure it is one of the most advanced V-6 offerings in the world. These include a dual-stage variable intake manifold (VIM). The VIM incorporates a switch in the manifold that automatically changes the plenum volume available for resonance tuning of the inlet flow path. A micro-hybrid engine control unit (ECU) which represents the latest in engine-management hardware, as well as with software, dictates every aspect of engine operation.
Other refinements include specially isolated cam covers which incorporate an isolated gasket around the cover perimeter and radial lip seals at the tubes through which each spark is inserted. Three pressure-actuated piston-cooling oil-jet assemblies in the block each douse the underside of the piston and the surrounding cylinder wall with cooling oil. This benefits piston temperatures, resulting in more engine power.
A polymer coating on the piston skirts helps the piston to track more smoothly and quietly in the bore, while a new oil pump design, the product of a highly specialized analysis of pump flow, prevents engine noise caused by oil aeration. A forged steel crankshaft delivers additional stiffness for better noise, vibration and harshness performance; ensures the durability required of high specific output variants; and provides an extra degree of robustness.
Improved performance
The 4.6-liter Northstar V-8 is a 90-degree DOHC four-valve-per-cylinder engine, with an aluminium block and cylinder heads and valve train with roller finger followers. The Northstar is equipped with a host of technologies, including four-cam continuously variable valve timing (VVT) for improved performance, refinement, economy and emissions, matched by low-restriction intake and exhaust manifolds and cylinder head ports, designed to ensure optimum airflow and cylinder-to-cylinder distribution for maximum performance and emissions control.
An extremely powerful, state-of-the-art, Engine Control Module (ECM), with a 16-bit, 24 MHz dual microprocessor, high memory capacity, and a redundant "safety" processor backing up the ETC enables the Northstar engine to provide its advanced capabilities. A transmission control module (TCM) controls the transmission with inputs from the ECM. Electronic throttle control provides additional driving refinement, by allowing the engine control system to precisely and seamlessly tailor vehicle performance to the driver demands.
A new air induction, redesigned for enhanced capacity and noise attenuation, system features tuned resonators, additional resonators in the clean air duct and use of isolator pads in the clean air duct mounting to reduce inlet noise. Polymer-coated pistons, a steel crankshaft, and cast-iron exhaust manifolds further reduce noise, vibration and harshness, while close-coupled catalytic converters, mounted directly adjacent to the exhaust manifolds aid lower emissions. They reach effective operating temperature more rapidly after engine start.
Transmissions
The V-8 and V-6 are mated to electronically controlled five-speed automatic transmissions - the Hydra-Matic 5L50-E is mated with the V-8, and the Hydra-Matic 5L40-E with the V-6. The 5L50-E is designed to handle the V-8's torque increase over that of the 5L40-E. Both transmissions incorporate Driver Shift Control (DSC) and Performance Algorithm Liftfoot (PAL) technologies. The Cadillac STS features limited slip differential, which mechanically limits wheel spin on all surfaces for improved vehicle performance during handling manoeuvres.
Driver Shift Control enables the driver to switch from automatic to a clutchless five-speed high-performance manual transmission. Once the driver moves the gearshift lever into DSC mode, a quick tap is all that is required for smooth, crisp upshifts or downshifts within a selected range.
Performance Algorithm Liftfoot inhibits upshifts while maintaining engine braking following continuous performance driving. The transmission control module (TCM) monitors driver behaviour to determine whether or not to enable this feature. For example, if the system detects a drop in vehicle speed prior to entering a turn or a lane change, up to two downshifts can occur to provide the driver with maximum vehicle performance.
Innovation: purposeful technology
From Keyless Access to HID headlamp technology, four-color head-up display and Bose Studio Surround Sound audio system, the Cadillac STS is equipped with purposeful technologies developed to ensure an outstanding vehicle experience in terms of luxury, comfort, convenience and safety.
The technological backbone of the STS comes in the form of the GM LAN Serial Data Electrical Architecture - a high- and low-speed data network that connects system modules and ensures that information is properly communicated and shared between them. In all, the STS is equipped with up to 27 modules, located throughout the vehicle, depending upon options selected. Each module sends and receives information sent via the GM LAN. This electrical architecture enables the host of purposeful technologies offered on the STS.
Keyless Access enables passive vehicle and trunk entry via a personalized, keyless fob. With the key fob in a pocket or purse, a person can approach a locked vehicle, pull the door handle and open the door. The same concept applies when opening the trunk. As a result, the need to pull keys out - or even the fob - to activate the door and trunk functions has been eliminated. The system uses passive and active antennas to detect the vehicle fob and its proximity to the vehicle.
Keyless Access start works in tandem with the vehicle security system, enabling the STS to be started with a momentary push of a button located on the instrument panel. To start the vehicle, the fob must be inside the vehicle, and the brake pedal depressed.
The STS can be equipped with Adaptive Cruise Control (ACC), which greatly increases the value and comfort of cruise control, especially in congested traffic situations. The system uses a radar sensor mounted at the front of the STS that is located behind the grille-mounted wreath & crest to detect objects in its path. If the lane ahead is clear, the system will maintain the set speed. When slower traffic is detected, the system will automatically adjust to a safe distance (which is selected by the driver) by using throttle control and limited braking.
Grade braking and audible alert
The ACC system used on the STS also incorporates two new features: grade braking and audible alert. With grade braking, the transmission will automatically downshift to maintain selected vehicle speed and distance, preventing overheating of brakes. An audible alert function operates when ACC is active, notifying the driver when he/she is too close to a preceding vehicle. All adaptive cruise displays are shown through the four-color, reconfigurable head-up display (HUD).
The ACC is combined with the latest day/night head-up display (HUD) application that is four-color and reconfigurable. The HUD projects into the driver's convenient line of sight, an infotainment data display, tap gear display, shift indicator display and ACC display as well as turn-by-turn directional navigation and audio band, frequency, and pre-set information - all based on driver preference. It is also configurable to five languages: English, French, Spanish, German, and Italian.
The STS is equipped with large 70-millimeter HID projector beam headlamps for outstanding forward- and spread-light performance. Two projector beams are stacked vertically in each headlamp housing; the upper projectors provide low-beam illumination, and all four projectors are illuminated for high-beam performance. The HID application includes headlamp washers, which are integrated flush to surface on the adjacent front fascia as well as a dynamic headlamp levelling system - a feature where the lens automatically aligns itself to the vertical height of the road based on vehicle pitch.
Bose surround sound audio system
The Cadillac STS Launch Edition features one of the industry's first OEM-installed surround sound audio systems. Developed by Bose, it incorporates 15 speakers and provides concert quality sound to both front occupants and passengers in the rear compartment.
The 300-watt system creates unmatched 5.1 channel surround sound quality and performance, with two 50-millimeter mid-high range speakers integrated in each of the driver and front passenger seat, two 2.5-inch full-range outboard speakers positioned in the instrument panel, four 3.5-inch full-range speakers located in the instrument panel, rear console and rear shelf, two 9-inch powered Neodynium (Nd) woofer assemblies located in the driver and front passenger doors, two 5.25-inch full-range speakers positioned in the rear doors, a 12-inch powered Nd sub woofer located in the center position of the rear shelf, a surround amplifier positioned on the rear shelf and a VNC microphone positioned to the driver's lower right.
The system incorporates proprietary processing technology from Bose, which makes two-channel audio information very rich and spacious. Base radio system features on the STS include dedicated presets for two drivers (up to 36 each) for AM, FM and XM Satellite Radio reception as well as the ability to seek across bands. The base system also includes expanded information display for XM, FM-RDS and CD MP3.
In-dash six-disc DVD changer
On the Launch Edition a factory-installed, in-dash six-disc DVD changer supports a variety of media formats and includes 5.1 channel surround sound. The system also incorporates dual media slots - one for entertainment and the other for DVD-based navigation - greatly reducing time changing media and ensuring full-time navigation capability. Media formats supported by the DVD system include DVD audio, DVD video, CD audio and MP3. Media types supported are CD/DVD ROM and CD/DVD-R. DVD video can only be activated when the vehicle is in "park".
When equipped with the uplevel infotainment package, the STS has an industry-largest 8-inch diagonal high-resolution full VGA infotainment display head with full touch screen and four-position tilt function. The display head - which is positioned high in the center stack and is flush with the surface of the instrument panel - provides unmatched clarity enabled by 800-by-480 pixel resolution. A large viewable area (approximately 104-by-174 mm) is 20 percent larger than most current offerings.
The four position tilt-screen incorporates memory recall and offers 5-, 10-, and 15-degrees of tilt, enabling the driver to select the best viewing angle based on environmental conditions.
Faster route calculation
The DVD-based navigation system available on the STS conducts route calculation 30 percent faster than current systems, displays freeway exit information (gas, restaurants, services) via expandable icons, and covers all roads and streets in Europe on a single map DVD. The system allows route planning to items stored in memory via voice commands and/or voice tags. A broad range of location search options is available, making location selection more user friendly.
The STS has cellular telephone accommodation for portable Bluetooth capable phones through the uplevel infotainment system, which enable hands-free operation, screen and voice dialing of phone numbers. An enhanced voice-recognition system on the STS offers continuous speech capability, multiple language support (English, French, Spanish, German, and Italian) and more than 150 voice commands, including those for infotainment and HVAC, among other functions.
Overview
From its Cadillac-signature styling to its performance capabilities, there's no mistaking the STS as anything but a contemporary Cadillac. Signature items styling include vertically stacked headlamps and light-emitting diode (LED) tail lamps, LED center high-mounted stop light (CHMSL), horizontal "spline lines" and dihedral-shaped hood.
With an overall length of 4985 mm, a wheelbase of 2957 mm and front/rear track of 1596/1581 mm the STS is the largest sedan in the GM Sigma-based family, which is also the foundation for Cadillac's entry-luxury CTS sedan, CTS V-series high-performance sedan and SRX luxury performance crossover. This ensures a particularly spacious and stylish interior, with an emphasis on high-quality fit and finish.
Premium quality materials are used throughout. Eucalyptus wood and aluminium trim appears on the steering wheel, center console, instrument panel and door armrests. Dual-firmness leather seats are specially tanned for a softer feel, with the added option of Tuscany leather upholstery. Natural grained surfaces on the door and instrument panel ensure an inviting, tactile touch, as do the headliner and interior pillars, which are soft backed and covered with a Monaco woven fabric.
The STS is offered with the 189 kW (257 horsepower) 3.6L V-6 VVT or the 239 kW (325 hp) Northstar 4.6L V-8. Both engines incorporate variable valve timing (VVT) and are mated to Cadillac's widely acclaimed five-speed automatic transmissions with Driver Shift Control. The 4.6L Northstar engine delivers 0-100 km/h acceleration in 6,2 seconds. With the V-6 the STS will achieve 0-100 km/h in 7,4 seconds.
Four-cam variable valve timing gives the V6 engine increased efficiency, with benefits in fuel economy, reduced emissions and a wide-ranging flexibility. 90 percent of the 3.6L V-6's peak torque is available across a broad operating range: from 1600 rpm to 5800 rpm. In addition, an electronically controlled throttle (ETC) effectively coordinates the driver's intentions with the actions of the various control components.
Real time damping
Integrated chassis control technologies combine high dynamic performance with a comfortable ride, including two-mode Magnetic Ride Control with performance or touring selections as standard on the V8. The electronically controlled magnetic-fluid based real time damping used on STS is the world's fastest-reacting suspension control system. Driver involvement is further enhanced by high-precision ZF steering gear and four-channel StabiliTrak which assists the vehicle in maintaining the driver's intended path by applying a brake force at any corner of the vehicle independent of the driver's use of the brake pedal. StabiliTrak is fully integrated with the traction control and ABS systems.
Plentiful, purposeful and driver oriented technical appointments include a Keyless Access system with a push button start; optional Adaptive Cruise Control (ACC) and reconfigurable four-color head-up display (HUD); heated and ventilated seats and heated steering wheel. The STS Elegance model comes highly specified as standard, with eight-way power seat adjustments for the driver and front occupant including a memory package which provides presets for two drivers and automatically adjusts the outside rear-view mirrors; power tilt and telescoping steering wheel position, radio and climate control settings.
Additional refinements on the special Launch Edition include the Eucalyptus wood trim package, heated front and rear seats, heated steering wheel, power lumbar adjustment on the front seats and an uplevel infotainment system, with a 15 speaker Bose 5.1 Surround Sound system with an integrated six-disc CD/DVD changer, an 8-inch (203 mm) VGA quality touch screen, Bluetooth capability, advanced voice recognition and an advanced navigation system.
Early in 2006, a high-performance Cadillac STS-V will also join the model line-up. This features a 4.4-liter DOHC Northstar V-8 SC engine with a positive displacement intercooled supercharger, the first supercharger ever on a production Cadillac delivering the highest horsepower rating of any production Cadillac engine to date.
The Cadillac STS is being built alongside its CTS, CTS-V and SRX stablemates at GM's state-of-the-art Lansing Grand River assembly center in Michigan. The facility recently received a J.D Power Gold Plant Award and was ranked the best assembly plant in North and South America in the 2004 J.D Power Initial Quality Study, in which Cadillac was voted number one amongst the toughest global luxury competition.
A distinctively bold offering of luxury and style
From its Cadillac-signature bold exterior styling to its inviting and carefully crafted interior, the STS is the product of unwavering attention to detail. More than 1,000 criteria points were strictly adhered to throughout development of the vehicle. The result combines a distinctive style with space, outstanding fit and finish, overall harmony, and purposeful innovation.
At first glance, there's no mistaking the STS as a contemporary Cadillac, with its vertically stacked headlamps and light-emitting diode (LED) tail lamps, signature LED CHMSL, horizontal spline lines, and dihedral-shaped hood. The STS carries this distinctive design vocabulary, heritage cues and styling characteristics found throughout the Cadillac product portfolio in a manner that is refined and sophisticated. It is intentionally crafted to meet the discriminating tastes of the performance luxury segment in which it competes - for the most discerning buyers in the automobile marketplace.
The overall shape lends a faster profile and more rake than its CTS sibling, but it's done so in the context of elegance and grace. Its doors-into-roof construction enables more tumblehome, the vehicle sides are sculpted inward, delivering a look of upscale rear-wheel-drive performance with a lower roof line, while maintaining a roomy interior. In addition, a wider tapering sail panel; lower, more sculptured hood; smoother wheel openings; and a tighter wheel-to-body relationship further communicate the agility of the STS, as well as sophistication and substance.
A wheelbase of 2957 cm and front/rear track of 1596/1581 mm, combined with a flush wheel-to-body relationship, ensures well-grounded appeal and presence. Overall, the STS is 4985 mm long, 1843 mm wide and 1464 mm high, making it the largest sedan offering in the GM Sigma-based family. As a result, the STS delivers ample interior space for front and rear passengers alike.
Luxury performance competence
Seven-spoke 17- or available nine-spoke 18-inch wheels and visible high-performance brake calipers and rotors leave no doubt about the STS' luxury performance competence. A wire mesh, electro-polished stainless steel lower grille reiterates the statement.
The rocker treatments on the vehicle are specific to the STS, bringing a more sculpted shape to the vehicle's lower line for more presence and refinement. A single-piece fascia design, which eliminates seams for a clean, uninterrupted appearance, enables excellent fit and finish. Vertically stacked headlamps, a traditional Cadillac cue, are slightly narrower and lower than seen on other Cadillac models. The headlamps incorporate large, dual 70-millimeter projector lenses encased in an aluminized, single piece bezel.
LED tail lamps are designed with indirect optics, an industry-first application, and incorporate 30 sources of illumination per unit. The use of indirect optics eliminates "pinpoints" of light normally associated with LEDs and enables an upscale, refined appearance when illuminated. On the STS, each tail lamp has two vertical arrays consisting of 15 LEDs, with each LED containing 20 optical facets. This configuration enables very precise illumination tuning and the design flexibility needed to meet both US domestic and export requirements.
The LED CHMSL on the STS is only 12-millimeters thick and consists of 78 points of illumination. An ingenious lens design incorporates the use of pillow optics, which again replaces a "pinpoint" appearance normally associated with LEDs with a smooth, refined output of light.
Single piece front fascia design
An integrated, precision-molded front fascia is constructed of thermal plastic olefin (TPO). Its single-piece design eliminates seams, and delivers outstanding dimensional execution to mating surfaces. The fascia incorporates upper and lower grilles and openings for headlamps, park/turn lamps, fog lamps and front side markers. In addition, HID headlamp washer elements are mounted flush to the fascia's surface for a smooth, clean appearance.
The rear styling of the STS is clean and uninterrupted, due in large part to a one-piece superplastic-formed aluminium decklid, with an integrated pocket on the trailing edge for the LED CHMSL. Use of the superplastic forming process has enabled integration of rear lighting elements without use of additional appliqués or trim. Styling lines, exhaust cut-outs, rear valance, rear fog lamps and the rear parking assist sensors are cleanly integrated into the overall design.
The styling of the STS is complemented by a wide range of exterior paint colors. These are: Blue Chip, Red Line, Black Raven, Silver Smoke, Sand Storm, Moonstone, Light Platinum, White Diamond and Silver Green Metallic.
Finely crafted, inviting interior
The interior of the STS is executed to extremely close and demanding tolerances, enabling a tight, well-crafted appearance throughout. Premium materials and surfaces are found throughout the interior. In-mould processed aluminium, which is particularly dent and mark resistant, is used for trim highlights on the Elegance model, with the Launch Edition offering Eucalyptus wood on the steering wheel, center console, instrument panel, and door armrests. A heated, leather-wrapped steering wheel is optionally available. Natural grained surfaces on the door and instrument panel ensure an inviting tactile touch, as do the headliner and interior pillars, which are soft backed and covered with a Monaco woven fabric.
The STS features dual-firmness seats (optionally available as heated and ventilated) that are specially tanned for a softer feel. The seat design's optimized dual-firmness strategy uses a pillow-like upper padding combined with a firmer seat cushion to achieve luxurious comfort as well as outstanding support. The standard Nuance leather seating surfaces or available Tuscany leather seats are available in Light Gray, Ebony or Cashmere finishes.
Eight-way seat adjustment
Power seat adjustments for the driver and front occupant provide eight-way seat adjustment with a memory package providing presets for two drivers, including settings for eight-way power driver/passenger seats with an easy exit driver seat; outside rear-view mirrors; power tilt and telescoping steering wheel position, radio and climate control settings. Four-way power lumbar adjustment and articulating head restraints are available on the Launch Edition.
The STS features analogue instrumentation, defined by bright accents and includes speedometer, tachometer, fuel gauge and engine water temperature. The Driver Information Center (DIC) is displayed in the gauge cluster, and has six-language capability (English, French, German, Italian, Japanese and Spanish). A standard electrochromic (light-sensitive auto dimming) interior rearview mirror is integrated with the interior.
Body, safety and security
From the inner structure to the architecture of the exterior sheet metal, the all-new Cadillac STS has been meticulously crafted to ensure delivery of the attributes expected of a luxury sedan. The STS features a body frame integral (BFI) structure, based on the premium GM Sigma rear-wheel-drive architecture. With a BFI structure, the upper body structure and sub-frames are engineered as a single unit, enabling a mass efficient, yet stiff, body structure.
BFI structures bring an ideal foundation for achieving sports sedan performance, resulting in a particularly rigid base structure with a beaming frequency of approximately 25 Hertz and significant torsional stiffness, some 13 percent greater even than the highly competitive Cadillac CTS. This provides a strong basis for the STS to combine great chassis dynamics with high levels of refinement. Additionally STS is equipped with a host of refinements to ensure a quiet ride and interior environment and impressive wind noise performance.
The Cadillac STS joins the CTS and SRX as the first vehicles in GM to be outfitted with a laminated front-of-dash panel - a key to reducing the transfer of engine compartment noise into the cabin. Also called "quiet steel", the application is found on all Sigma architecture-based vehicles.
Noise-damping 'blanket'
The front-of-dash panel consists of two thin pieces of steel held together by composite adhesive. A sophisticated bonding process ensures the steel will not resonate noise, and damps noise transfer significantly when compared to conventional applications. A front-of-dash mat constructed of a 28-millimeter thick thermal plastic olefin (TPO) cast foam material also reduces powertrain noise transfer into the cabin. The mat, essentially a noise-damping blanket on the engine side of the dash panel, is applied with a glove-like fit and closes out all cavities in the panel.
All chassis-to-body structure interfaces (i.e., suspension brackets or cradle attachments) on the STS have been designed to improve stiffness and structure, thus further isolating low-frequency noise from the cabin. Each of the interfaces has essentially been "tuned" through shape or material thickness to ensure a robust, stiff structure that effectively minimizes vibrations and related transfer of noise from road irregularities, engine, prop shaft, and other inputs.
In order to add greater reinforcement to the center tunnel of the STS, which serves as the "backbone" of the vehicle, a tubular structured U-shaped "strap" was added for tension and compression, again further improving the vehicle's overall stiffness. It also helps reduce vibration to the floor pan and rear seats. A constraint layer also is implemented into the tunnel structure - inner and outer steel structures are mated together in a sandwich form. As a result, the two pieces of steel dampen each other, reducing the transfer of noise and vibration into the cockpit.
Reducing noise level
To attenuate noise transfer from the shock towers into the passenger compartment, all shock towers are applied with a constraint layer, two pieces of metal that sandwich a rubber viscous material, making up the structure of each shock tower. This application again significantly reduces the noise level in the passenger compartment. Similarly both rear wheelhouses on the STS are constructed of sandwiched steel structures that mate together as inner and outer structures, dampening each other, greatly reducing the resonation of noise into the rear passenger compartment.
A front tunnel barrier is applied under the carpet on the STS to ensure superior isolation from driveline acoustics. The barrier, which runs from the dash panel rearward on either side of the tunnel where it meets the floor, is constructed of a lightweight composite with outstanding noise damping characteristics.
An acoustic laminated windshield is a key enabler of the Cadillac STS model's wind noise performance. While the windshield itself is thinner than traditional applications to reduce mass, a four-layer construction allows it to deliver the acoustic performance of thicker glass. Two layers of glass sandwich a safety laminate and an acoustical-grade vinyl sheet laminate, enabling a marked reduction in wind noise. Laminated front side glass also provides significant improvements in wind and external noise performance.
Further, typically Cadillac, attention to detail is demonstrated by the use of lightweight damping material throughout the vehicle cabin to address the high- and mid-range frequencies normally requiring heavier deadening materials. The material is a foil/rubber acoustical damping compound that is adhesively applied to the inner sheet metal, a first-time Sigma architecture application, while low weight, high-absorption trunk acoustics effectively damp noise and vibration from the luggage compartment.
Lower profile, structure-less windshield wipers deliver a wind noise reduction when compared with conventional applications. Sometimes called "flat blades", the wipers replace an arm structure, a common source of noise when wind travels through and around it, with a flexible airfoil surface that runs along the top of the blade. The airfoil is "tuned" to the shape of the windshield, ensuring a lower profile and superior contact with the windshield at all positions.
The doors-into-roof construction on the STS eliminates the need for molding along the top of side window glass and ensures consistent surfaces around the elements. This door execution, inspired by high-performance aircraft, enables extremely tight gap tolerances, removes a source of wind noise and plays a primary role in the integrated, clean and sleek appearance of the STS. A triple seal architecture around all four doors reduces vehicle interior noise levels. Three seal sets work together to effectively seal the passenger compartment from wind, water, and other elements.
Sculpted surface
The aluminium decklid on the STS luggage compartment is a complex shaped form produced using an advanced superplastic forming (SPF) process, an execution that enables a sculpted surface and outstanding dimensional accuracy. A traditional stamping execution of either steel or aluminium would have resulted in a two-piece execution of the decklid, requiring the use of additional exterior trim.
In the superplastic forming process, aluminium is heated to a state of plasticity then formed into a die cavity using air pressure. The final result is a single-piece form, with an integrated pocket for the light emitting diode (LED) CHMSL as well as the backup lamps, which ensures a clean surface throughout the contoured shape of the decklid.
The STS maintains Cadillac's long-standing reputation for delivering a safe occupant environment in premium vehicles. Structural enhancements contributing to the excellent crash performance capability of the STS include a two-piece magnesium cross-vehicle structure for side and front crash protection, octagonal engine rails to enhance high-speed offset crash protection and a one-piece hydroformed A-pillar/roof rail structure that brings added upper structural rigidity and enhanced strength during side and frontal impacts.
Inner and outer rocker panels are constructed of strong, ultra-high strength steel and longitudinal rails are injected with structural foam to protect and maintain their geometry during an impact. The foam adds to overall body structure stiffness and contributes to preventing intrusion around occupants' feet during high-speed offset impacts. Rear rail inner sections are constructed of high-strength dual phase steel - a first-time application on the Sigma architecture. Dual phase steel brings outstanding characteristics for supporting crashworthiness deformation.
Six airbags as standard
The STS has a total of six airbags offered as standard equipment, which help to maximize protection in high-speed crashes while minimizing the risk of injury to out-of-position occupants. Airbags include a dual stage driver's front airbag and a front passenger airbag, driver's and front passenger seat-mounted airbags for thorax protection, along with roof rail side curtain airbags giving head protection with front and second row coverage.
In the case of the dual-stage airbags, when the air-bag system's central control unit, the Sensing Diagnostic Module (SDM), detects an impact, it determines whether the crash is severe enough to trigger a deployment, and whether the primary amount of inflation is sufficient or if both primary and secondary stage inflation is required. The primary stage alone will deploy in most frontal impacts requiring the supplemental protection of an airbag, while the secondary stage also will deploy in very severe frontal collisions.
The SDM also detects side impacts and determines whether the rail-curtain and side seat-mounted (thorax protection) air bags should deploy. These air bags act like a protective curtain, unfolding from the roof rail between the A and C pillars. When the bag deploys, it is biased toward the window to help maximize protection.
The SDM also activates the safety belt pretensioner, which reduces slack in the safety belt webbing. This helps secure occupants in the seat to better hold them in position so they decelerate at the same rate as the car. The safety belts are equipped with 'frictionless' D-rings and low-effort retractors so there is minimum pressure on the occupant, making them more comfortable to wear. The retractors also are energy absorbing.
Second row seats have three-point safety belts in all positions. The second-row seats of the STS come equipped with the LATCH system to simplify child seat installation. These anchors, which are secured to the body structure, are provided in all three rear-seat positions.
Occupant security features
Occupant security is provided with a number of standard and available features, including child security door locks so a parent can choose to prevent their child from opening the rear doors from the inside and a power window lockout so control of the windows can be limited to the driver controls. An engine immobilizer and theft deterrent system is standard as is delayed entry lighting, which keeps the interior lights on after the driver enters and until the vehicle is started.
The Standard Remote Keyless Entry also includes a panic button on the key fob, which turns on all the lights except the headlamps, sounds the horn and activates content theft deterrent and anti-lockout features. Battery rundown protection automatically shuts off any electrical system inadvertently left on after a period of time before the battery runs down. A child entrapment release lever is fitted in the trunk and further peace of mind is offered with the option of a tire pressure monitoring system.
Chassis: a perfect balance of ride and handling
A host of chassis refinements ensure that the STS hits the perfect balance of smooth ride and entertaining handling. Road impacts and other harsh inputs are effectively absorbed and dissipated through ride-tuned tires, dampers, suspension components and bushings, as well as improved structure in body-to-chassis interfaces and additional refinements in the engine mounts. The result is a ride that keeps drivers fresh and comfortable without sacrificing the driving experience.
Among the many refinements found in the front suspension components is the use of aluminium for both the upper and lower control arms, suspension joints and brake callipers. This reduces unsprung mass, requiring less damping and dynamic wheel control, contributing to more nimble handling and better road-holding ability. Hydraulic control arm front bushings are used to provide optimum motion control while minimizing high-speed road vibration, by damping energy transmitted to the vehicle structure. A hollow front stabilizer bar on all models brings weight savings and added stability. The fully independent multilink rear suspension with fully isolated sub frame is an uncompromising design with excellent suspension kinematics that enables outstanding ride and handling performance.
At the same time, the other features of the suspension architecture give it the ability to control loads and maintain stability during dynamic driving situations, striking a balance between ride quality and high-performance handling capability. Other rear suspension features include weight-saving aluminium upper control arms, knuckles and brake callipers, along with hollow rear stabilizer bars. The rear suspension is fully isolated to reduce road and driveline noise.
Rear damping is provided by Nivomat load-levelling shocks, a fully automatic hydraulic level-regulating system with integrated shock absorber, adapt automatically to different loads and road conditions.
Front shock absorbers on base models are monotube dampers from Sachs, a leading German producer of high-performance shock absorbers, which provide highly responsive damping of road inputs.
The STS V8 model also offers as standard the award-winning Magnetic Ride Control (MR) system which uses electronic control of damping forces in a continuously variable real-time damping system to provide exceptional responsiveness, greatly increased driver control and increased tire contact with the road, regardless of road surface.
The MR system uses valveless damping and magneto-rheological (MR) fluid technology. The fluid is a suspension of iron particles in a synthetic hydrocarbon-base fluid. When the system is activated, the particles are magnetized and aligned into fibrous structures, changing the flow resistance of the fluid. By controlling the current to an electromagnetic coil inside the piston of the damper, the system varies the fluid viscosity continuously in response to road surface conditions over a broad damping range.
Increased wheel contact
Damping levels are adjusted up to 1,000 times per second, making the system exceptionally responsive and providing increased wheel contact on even the roughest road. Reduced wheel bounce ensures an even ride by virtually eliminating heave, pitch and roll. It also delivers excellent roll control during transient steering and evasive manoeuvres.
A set of wheel-to-body sensors detects changes in the road surface and the system controller adjusts the fluid viscosity to vary the damping force accordingly, providing a flatter ride during cornering and reduced diving or squatting during braking and acceleration.
The MR system on the STS is among the first to make available two selectable settings accessed through the infotainment display head - performance or touring modes. The performance mode may be used where road conditions or personal preference demand more control; the setting provides more "feel" or responsiveness to road conditions. The touring mode is available for normal city and highway driving and provides a smoother, more accommodating ride.
Enhanced steering input is offered by optional ZF Servotronic II rack-and-pinion speed-sensitive steering gear with 18.2:1 variable ratio and speed-sensitive variable assist. The turning radius of the Cadillac STS is just 11.5 meters. The standard StabiliTrak system on the STS is a sophisticated four-channel (independent control to all four corners of the vehicle) active handling system. It links the vehicle's dynamic control systems to assist the driver in maintaining control under demanding or adverse conditions such as wet, snow-covered or icy roads, tight turns, and evasive manoeuvres.
The STS is equipped with four-wheel-vented disc brakes with standard four-wheel antilock braking system (ABS) and traction control system (TCS). The brakes feature vented rotors consistent with the demands of a luxury performance sedan. Base brake package rotor dimensions are 303 x 32 mm front and 298 x 26 mm rear. Uplevel brake package rotor dimensions measure 323 x 32 mm front and 320 x 26 mm rear.
Panic Brake Assist (PBA), which senses emergency braking by detecting the speed or force the driver applies to the brake pedal and boosts the power as needed, is incorporated into the brake system. Under certain conditions, the panic brake assist may activate the ABS more quickly and easily than vehicles without the feature, potentially reducing overall stopping distance by eliminating the delay caused by not braking hard enough and/or soon enough. The system also features Dynamic Rear Brake Proportioning, which regulates braking pressure to optimize stopping distances and control under all vehicle-loading conditions.
The Cadillac STS is available with 17- or 18-inch wheels. V6 models use 17 x 7.5 cast aluminium front wheels with P235/50R17 tires and 17 x 8.0 rear wheels with P255/45R17 tires. Cadillac STS V8 models feature
18 x 8.5-inch flow-formed aluminium wheels with high performance 255/45R18 tires on all four corners.
Powertrain: refined power with wide-ranging flexibility
The new Cadillac STS is offered with two world-class powertrains. The 3.6L V-6 VVT develops 189 kW (257 horsepower) and 342 Nm of torque and the 4.6L Northstar V-8 develops 239 kW (325 hp) with 427 Nm of torque. The V-6 and V-8 power units are both mated to electronically controlled five-speed automatic transmissions - the Hydra-Matic 5L40-E is mated with the V-6, and the Hydra-Matic 5L50-E is designed to handle the V-8's increased torque. The 4.6-liter Northstar accelerates from 0-to-100 km/h in 6.2 seconds. With the V-6 the STS achieves 0-100 km/h acceleration in 7.4 seconds.
The 60-degree 3.6-liter V-6 is a highly refined, DOHC four-valves-per-cylinder engine with all-aluminium construction. The adoption of fully variable valve timing for both intake and exhaust valves provides outstanding fuel economy, emissions reduction and a wide-ranging flexibility. 90 Percent of the 3.6L V-6's peak torque is available across a remarkably broad operating range: from 1,600 rpm to 5,800 rpm. In addition, an electronically controlled throttle (ETC) effectively coordinates the driver's intentions with the actions of the various control components.
Numerous design features were incorporated into the 3.6-liter engine to ensure it is one of the most advanced V-6 offerings in the world. These include a dual-stage variable intake manifold (VIM). The VIM incorporates a switch in the manifold that automatically changes the plenum volume available for resonance tuning of the inlet flow path. A micro-hybrid engine control unit (ECU) which represents the latest in engine-management hardware, as well as with software, dictates every aspect of engine operation.
Other refinements include specially isolated cam covers which incorporate an isolated gasket around the cover perimeter and radial lip seals at the tubes through which each spark is inserted. Three pressure-actuated piston-cooling oil-jet assemblies in the block each douse the underside of the piston and the surrounding cylinder wall with cooling oil. This benefits piston temperatures, resulting in more engine power.
A polymer coating on the piston skirts helps the piston to track more smoothly and quietly in the bore, while a new oil pump design, the product of a highly specialized analysis of pump flow, prevents engine noise caused by oil aeration. A forged steel crankshaft delivers additional stiffness for better noise, vibration and harshness performance; ensures the durability required of high specific output variants; and provides an extra degree of robustness.
Improved performance
The 4.6-liter Northstar V-8 is a 90-degree DOHC four-valve-per-cylinder engine, with an aluminium block and cylinder heads and valve train with roller finger followers. The Northstar is equipped with a host of technologies, including four-cam continuously variable valve timing (VVT) for improved performance, refinement, economy and emissions, matched by low-restriction intake and exhaust manifolds and cylinder head ports, designed to ensure optimum airflow and cylinder-to-cylinder distribution for maximum performance and emissions control.
An extremely powerful, state-of-the-art, Engine Control Module (ECM), with a 16-bit, 24 MHz dual microprocessor, high memory capacity, and a redundant "safety" processor backing up the ETC enables the Northstar engine to provide its advanced capabilities. A transmission control module (TCM) controls the transmission with inputs from the ECM. Electronic throttle control provides additional driving refinement, by allowing the engine control system to precisely and seamlessly tailor vehicle performance to the driver demands.
A new air induction, redesigned for enhanced capacity and noise attenuation, system features tuned resonators, additional resonators in the clean air duct and use of isolator pads in the clean air duct mounting to reduce inlet noise. Polymer-coated pistons, a steel crankshaft, and cast-iron exhaust manifolds further reduce noise, vibration and harshness, while close-coupled catalytic converters, mounted directly adjacent to the exhaust manifolds aid lower emissions. They reach effective operating temperature more rapidly after engine start.
Transmissions
The V-8 and V-6 are mated to electronically controlled five-speed automatic transmissions - the Hydra-Matic 5L50-E is mated with the V-8, and the Hydra-Matic 5L40-E with the V-6. The 5L50-E is designed to handle the V-8's torque increase over that of the 5L40-E. Both transmissions incorporate Driver Shift Control (DSC) and Performance Algorithm Liftfoot (PAL) technologies. The Cadillac STS features limited slip differential, which mechanically limits wheel spin on all surfaces for improved vehicle performance during handling manoeuvres.
Driver Shift Control enables the driver to switch from automatic to a clutchless five-speed high-performance manual transmission. Once the driver moves the gearshift lever into DSC mode, a quick tap is all that is required for smooth, crisp upshifts or downshifts within a selected range.
Performance Algorithm Liftfoot inhibits upshifts while maintaining engine braking following continuous performance driving. The transmission control module (TCM) monitors driver behaviour to determine whether or not to enable this feature. For example, if the system detects a drop in vehicle speed prior to entering a turn or a lane change, up to two downshifts can occur to provide the driver with maximum vehicle performance.
Innovation: purposeful technology
From Keyless Access to HID headlamp technology, four-color head-up display and Bose Studio Surround Sound audio system, the Cadillac STS is equipped with purposeful technologies developed to ensure an outstanding vehicle experience in terms of luxury, comfort, convenience and safety.
The technological backbone of the STS comes in the form of the GM LAN Serial Data Electrical Architecture - a high- and low-speed data network that connects system modules and ensures that information is properly communicated and shared between them. In all, the STS is equipped with up to 27 modules, located throughout the vehicle, depending upon options selected. Each module sends and receives information sent via the GM LAN. This electrical architecture enables the host of purposeful technologies offered on the STS.
Keyless Access enables passive vehicle and trunk entry via a personalized, keyless fob. With the key fob in a pocket or purse, a person can approach a locked vehicle, pull the door handle and open the door. The same concept applies when opening the trunk. As a result, the need to pull keys out - or even the fob - to activate the door and trunk functions has been eliminated. The system uses passive and active antennas to detect the vehicle fob and its proximity to the vehicle.
Keyless Access start works in tandem with the vehicle security system, enabling the STS to be started with a momentary push of a button located on the instrument panel. To start the vehicle, the fob must be inside the vehicle, and the brake pedal depressed.
The STS can be equipped with Adaptive Cruise Control (ACC), which greatly increases the value and comfort of cruise control, especially in congested traffic situations. The system uses a radar sensor mounted at the front of the STS that is located behind the grille-mounted wreath & crest to detect objects in its path. If the lane ahead is clear, the system will maintain the set speed. When slower traffic is detected, the system will automatically adjust to a safe distance (which is selected by the driver) by using throttle control and limited braking.
Grade braking and audible alert
The ACC system used on the STS also incorporates two new features: grade braking and audible alert. With grade braking, the transmission will automatically downshift to maintain selected vehicle speed and distance, preventing overheating of brakes. An audible alert function operates when ACC is active, notifying the driver when he/she is too close to a preceding vehicle. All adaptive cruise displays are shown through the four-color, reconfigurable head-up display (HUD).
The ACC is combined with the latest day/night head-up display (HUD) application that is four-color and reconfigurable. The HUD projects into the driver's convenient line of sight, an infotainment data display, tap gear display, shift indicator display and ACC display as well as turn-by-turn directional navigation and audio band, frequency, and pre-set information - all based on driver preference. It is also configurable to five languages: English, French, Spanish, German, and Italian.
The STS is equipped with large 70-millimeter HID projector beam headlamps for outstanding forward- and spread-light performance. Two projector beams are stacked vertically in each headlamp housing; the upper projectors provide low-beam illumination, and all four projectors are illuminated for high-beam performance. The HID application includes headlamp washers, which are integrated flush to surface on the adjacent front fascia as well as a dynamic headlamp levelling system - a feature where the lens automatically aligns itself to the vertical height of the road based on vehicle pitch.
Bose surround sound audio system
The Cadillac STS Launch Edition features one of the industry's first OEM-installed surround sound audio systems. Developed by Bose, it incorporates 15 speakers and provides concert quality sound to both front occupants and passengers in the rear compartment.
The 300-watt system creates unmatched 5.1 channel surround sound quality and performance, with two 50-millimeter mid-high range speakers integrated in each of the driver and front passenger seat, two 2.5-inch full-range outboard speakers positioned in the instrument panel, four 3.5-inch full-range speakers located in the instrument panel, rear console and rear shelf, two 9-inch powered Neodynium (Nd) woofer assemblies located in the driver and front passenger doors, two 5.25-inch full-range speakers positioned in the rear doors, a 12-inch powered Nd sub woofer located in the center position of the rear shelf, a surround amplifier positioned on the rear shelf and a VNC microphone positioned to the driver's lower right.
The system incorporates proprietary processing technology from Bose, which makes two-channel audio information very rich and spacious. Base radio system features on the STS include dedicated presets for two drivers (up to 36 each) for AM, FM and XM Satellite Radio reception as well as the ability to seek across bands. The base system also includes expanded information display for XM, FM-RDS and CD MP3.
In-dash six-disc DVD changer
On the Launch Edition a factory-installed, in-dash six-disc DVD changer supports a variety of media formats and includes 5.1 channel surround sound. The system also incorporates dual media slots - one for entertainment and the other for DVD-based navigation - greatly reducing time changing media and ensuring full-time navigation capability. Media formats supported by the DVD system include DVD audio, DVD video, CD audio and MP3. Media types supported are CD/DVD ROM and CD/DVD-R. DVD video can only be activated when the vehicle is in "park".
When equipped with the uplevel infotainment package, the STS has an industry-largest 8-inch diagonal high-resolution full VGA infotainment display head with full touch screen and four-position tilt function. The display head - which is positioned high in the center stack and is flush with the surface of the instrument panel - provides unmatched clarity enabled by 800-by-480 pixel resolution. A large viewable area (approximately 104-by-174 mm) is 20 percent larger than most current offerings.
The four position tilt-screen incorporates memory recall and offers 5-, 10-, and 15-degrees of tilt, enabling the driver to select the best viewing angle based on environmental conditions.
Faster route calculation
The DVD-based navigation system available on the STS conducts route calculation 30 percent faster than current systems, displays freeway exit information (gas, restaurants, services) via expandable icons, and covers all roads and streets in Europe on a single map DVD. The system allows route planning to items stored in memory via voice commands and/or voice tags. A broad range of location search options is available, making location selection more user friendly.
The STS has cellular telephone accommodation for portable Bluetooth capable phones through the uplevel infotainment system, which enable hands-free operation, screen and voice dialing of phone numbers. An enhanced voice-recognition system on the STS offers continuous speech capability, multiple language support (English, French, Spanish, German, and Italian) and more than 150 voice commands, including those for infotainment and HVAC, among other functions.