General Motors' first North American application of direct injection on a gasoline engine was the 2.0L turbo four cylinder in the Pontiac Solstice GXP/Saturn Sky Red Line. The direct injection allowed the engine to produce more power while getting better fuel economy than the base 2.2L engine.
Now the DI love is spreading to the 3.6L V-6 in the Cadillac STS. The updated engine gets an fifteen percent bump in power to 298 hp and six percent increase in torque. The final fuel economy numbers aren't available yet, but they are expected to improve compared to the original engine. The more precise fuel control also results in a twenty-five reduction in cold-start hydrocarbon emissions. The variable valve timing is also used to delay exhaust valve closing under certain conditions allowing exhaust gases to be pulled back into the combustion chamber. This lowers the combustion temperature and reduces NOx emissions without having to use an EGR system.
GM expects to build 200,000 direct injected engines annually by the end of 2008 and will expanding the use of direct-injection the coming years. The STS press release is after the jump.
[Source: General Motors]
ENHANCED 2008 CADILLAC STS DELIVERS SIGNATURE STYLING AND ADVANCED PERFORMANCE TECHNOLOGY
NEW YORK – The 2008 Cadillac STS, featuring refreshed signature styling inside and out; a new, standard 298-horsepower (222 kW) V-6 engine; and a host of new vehicle technologies, debuts at next week's New York Auto Show, April 6-15, at the Jacob Javits Convention Center.
"For the past two decades, the Cadillac STS has been a showcase of luxury, performance and technology," said Jim Taylor, Cadillac general manger. "The new 2008 STS extends that heritage with a bold new look, the debut of a new, high-tech standard engine and some of the industry's most advanced safety technology."
Refreshed design, inside and out
With overall dimensions slightly increased, the new STS conveys more of the design flair that has become a Cadillac signature. Up front, the dual-textured, multi-faceted grille first seen on the Sixteen concept and incorporated on both the Escalade and soon-to-be-launched 2008 CTS, has been adapted to the STS, giving the luxury performance sedan a more sophisticated appearance. Vertically stacked headlamps with large, dual 70mm projector lenses are encased in an aluminized, single-piece bezel. High Intensity Discharge (HID) headlamps are now available on V-6 models.
Also available on V-6 models for the first time are Intellibeam headlamps. The headlamps automatically switch gradually from high beam to low beam when vehicles approach or the vehicle is approaching taillamps. The lower front fascia is a new design, with a new intake and grille patterned after current Cadillac 'V' cues. New, narrower side marker lamps are added.
Similarly, side air extractors, again inspired by the Sixteen and Escalade, are now incorporated in the front fenders of the STS.
New styling touches also include chrome-plated door handles and new lower rocker moldings that blend into the lower line of the vehicle for more presence and refinement.
At the rear, the new fascia is now body-color, and is highlighted with the addition of polished, aluminum three-inch exhaust tips.
New, polished 18-inch by 8-inch aluminum 14-spoke wheels are available. For these available wheels, Michelin W-rated, 235/50R18 tires are used up front, and the rear wheels are fitted with 255/45R18 all-season radials.
Inside, STS's luxurious interior includes a new steering wheel with available genuine Sapele Pommele wood trim. Sapele is an exotic wood more commonly used in fine furniture and musical instruments. A heated steering wheel also is available. The center stack of the instrument panel is revised with the addition of wood trim that has new metallic surroundings.
New, available features for the STS include a head-up display on V-6 models. The head-up display projects key driving information (such as speedometer ratings) onto the windshield, enabling drivers to keep their eyes on the road.
STS adds direct-injection V-6
For 2008, STS will be the first GM vehicle equipped with a new 3.6-liter direct-injected V-6 engine. The new base powerplant, with 298 horsepower (222 kW), delivers 40 more horsepower; and torque is increased to 268 lb.-ft. (371 Nm) – up from 252 lb.-ft. (348 Nm) on the current base engine.
The new direct-injected 3.6L will be mated to the Hydra-Matic 6L50 six-speed automatic transmission, the first pairing of this transmission with a V-6 engine. Additionally, the STS V-6 will continue to be available with all-wheel drive (AWD) for 2008.
Advantages of the new direct-injected engine include a 25-percent reduction in cold-start hydrocarbon emissions. Additionally, despite the 15-percent increase in power, fuel economy is expected to increase slightly.
Lane departure technology debuts
Continuing Cadillac's commitment to using advanced safety features, the 2008 STS will offer new features including a new performance handling package; enhanced variable-effort steering with StabiliTrak on V-8 models; and new lane departure warning and blind side alerts.
The new performance handling package will be available for V-8-equipped rear-wheel-drive and all-wheel-drive models and V-6-equipped rear-drive models. The package includes 18-inch by 8.5-inch aluminum alloy, chrome-plated wheels fitted with new P255/45R18 Michelin Pilot Sport summer-only tires.
Brembo brakes with four-piston calipers provide enhanced braking, with front rotors measuring 14-inch by 1.2-inch (355mm x 32mm) coupled with 14.4-inch by 1.1-inch (365mm x 28mm) rear rotors. All four rotors are vented.
In addition to controlling brakes and reducing engine power, the latest iteration of StabiliTrak combines active front steering to turn the front wheels into the skid when rear wheels lose traction. The system includes a new steering motor assembly combined with computer-driven electronic controls that measure wheel slippage at all four wheels independently during acceleration, braking and adverse road conditions.
To help alert drivers to maintain their position on the road, the STS will be available with a new lane departure system. Controlled by a camera located in the rearview mirror that reads the lines in the road, the system will alert drivers when they have strayed into another lane. Drivers will get both audible and visual alert cues.
Another new feature is an available blind spot alert system. The radar-based convenience feature will provide drivers with a visual alert that appears on the outside rearview mirror when vehicles appear in a specified side zone.
The 2008 STS is expected to be available in Cadillac dealerships by mid-summer. Introductory pricing will be announced at a later date.