Cadillac STS

Press Release

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.