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2005 PONTIAC GRAND PRIX GXP PACKS V-8 POWER

ANAHEIM, Calif. — Pontiac announced production plans for the 2005 Grand Prix GXP - a high-performance sedan equipped with more refined interior appointments, distinctive exterior appearance, sport-tuned suspension and a new 5.3-liter LS4 V-8 engine producing an estimated 290 horsepower.

The Grand Prix GXP is the latest GXP concept to reach production, following this year's successful launch of the V-8-powered Bonneville GXP, which currently accounts for about 30 percent of all Bonneville sales. It is the first Grand Prix model since 1987 to offer a V-8 engine and it is the first Pontiac equipped with Displacement On Demand (DOD) technology, which can provide up to a 12 percent improvement in fuel economy by seamlessly deactivating half of the engine's cylinders in certain light load conditions.

Grand Prix GXP is expected to deliver 0-60 performance of approximately six seconds.

"The GXP performance series is about more than extra horsepower - it's an extension of Pontiac's total performance lineup," said Jim Bunnell, Pontiac-GMC general manager. "We've taken a systematic approach to elevating all aspects of the Grand Prix's dynamics, ratcheting up everything from handling to styling and refinement, to give performance-oriented customers the exhilarating driving experience they desire."

Product highlights of the Grand Prix GXP include:
LS4 5.3-liter V-8 engine with Displacement On Demand technology
290 horsepower (estimate)
325 lb.-ft. of torque (estimate)
High-performance Hydra-Matic 4T65-E four-speed electronically controlled transmission with TAPShift
GXP-specific exterior styling, including front fascia, rear fascia, rocker extensions and badging
Polished 18-inch forged aluminum wheels and performance W-rated tires
Reduced ride height
Bilstein gas-charged struts and higher-rate springs
High-performance four-wheel disc brake system with aluminum calipers, 12.7-inch vented and cross-drilled front rotors and 12-inch vented and cross-drilled rear rotors
GXP-specific interior appointments, including gauge faces, door sill plates and embroidered floor mats
The Grand Prix GXP has an aggressive, hunkered-down look due to a re-tuned suspension that lowers the vehicle approximately 9 mm. The aggressive look is accented with a new front fascia with revised, chrome-ringed grille inserts and lower air inlets, as well as a new rear fascia that gives the car a more tightly wrapped appearance. The new front and rear fascias are complemented by rocker extensions.

GXP badges on the vehicle's doors and prominent exhaust outlets in the rear fascia are stylish clues to the car's performance. Low profile performance tires are mounted on 18-inch polished forged aluminum wheels to complete the exterior package.

Inside, the GXP delivers a higher level of refinement, with rich, Ultralux suede inserts for the leather seating. Brushed aluminum trim accents - a GXP hallmark - are used inside, too, along with brushed aluminum-style doorsill plates. The instrument gauge cluster has a unique look and also wears the GXP logo.

Return of the V-8
The heart of the Grand Prix GXP is the new LS4 5.3-liter V-8 - the first time in almost 20 years that a V-8 engine has been offered in a Grand Prix. It also is the first application ever for the small-block V-8 in a front-wheel-drive configuration.

Engineered specifically for front-drive layouts, the LS4 produces an estimated 290 horsepower and 325 lb.-ft. of torque - with 90 percent of torque available from 1500 rpm to 5200 rpm. It also incorporates Displacement On Demand (DOD) technology, which debuted in 2005 GM extended midsize SUVs equipped with the Vortec 5.3-liter LH6 V8 engine.

With the LS4, DOD technology enables fuel economy gains of up to 12 percent in certain driving conditions by reducing the number of cylinders engaged in the combustion process. A sophisticated engine controller determines when to deactivate cylinders, allowing the engine to maintain vehicle speed in lighter-load conditions such as highway cruising. When the cylinders are deactivated, the engine effectively operates as a V-4, with alternate cylinders on each cylinder bank disabled. The engine returns to V-8 mode the instant the controller determines the vehicle speed or load requires additional power. The process is seamless and virtually imperceptible.

"There's nothing like the satisfying feel of a V-8 engine and the LS4 provides a level of performance rarely available in competitors' vehicles," said David Muscaro, assistant chief engineer of small-block V-8 for passenger cars. "But when all eight cylinders aren't required to maintain performance, DOD technology effectively turns the engine into a more efficient V-4."

The all-aluminum LS4 is based on the Gen IV small-block architecture, but is modified to accommodate the "east-west" mounting position of the Grand Prix's front-wheel-drive chassis. To fit the "sideways" positioning in the Grand Prix, several changes were made to reduce the engine's overall length, including the use of a shorter crankshaft and a single-belt accessory drive system.

Other LS4 features include:
Aluminum engine block with cross-bolted main bearing caps
Aluminum high-flow cylinder heads similar to the 6.0-liter LS2 V8
Full-floating pistons
Lightweight, three-piece friction-welded composite intake manifold
10:1 compression ratio for fuel-efficient performance
Unique camshaft designed to accommodate DOD technology
Electronic throttle control integrated with new engine controller
GM Oil Life System to minimize required oil changes
Iridium-tipped spark plugs for 100,000 mile service
The LS4 engine is mated to a high-performance Hydra-Matic 4T65-E electronically controlled four-speed automatic transmission with standard TAPShift. The transmission is strengthened to handle the prodigious torque of the V-8 engine.

Quick reflexes
Complementing the torque and horsepower of the LS4 V-8 is a revamped suspension that takes the Grand Prix GXP's road feel to a more responsive level. Bilstein gas-charged struts provide precise damping control and higher rate springs help improve the driver's connection to the road. A ride height reduction of approximately 9 mm and a new 17.2-mm hollow rear stabilizer bar help the GXP negotiate turns with less body roll.

An upgraded brake system was developed to match the Grand Prix GXP's performance capability. The system consists of four-wheel disc brakes designed for high-performance driving and a standard Bosch four-channel ABS system. The brake rotors at all four corners are larger than other Grand Prix models - 12.7-inch-diameter in front and 12-inch-diameter in the rear - and are vented and cross-drilled. They are acted upon by high-performance aluminum calipers, with twin-piston calipers in the front. The brake system provides superior stopping capability.

Connecting the high-performance suspension and brake systems to the tarmac is a set of premium 18-inch polished forged aluminum wheels and high-performance tires. The front wheels measure 18 x 8 inches and are mounted on P255/45R18 W speed-rated tires, while the rear wheels measure 18 x 7 inches and are wrapped by P225/50R18 W speed-rated tires. The wider front wheels help the Grand Prix GXP achieve more neutral cornering characteristics, while bolstering overall handling and braking of the high-performance sedan. In short, the wide front wheels and tires help the Grand Prix GXP push the limits of front-wheel-drive handling capability. Maganasteer II and StabiliTrak are standard.

The Grand Prix GXP is scheduled to start production in the first quarter of 2005. Pricing will be announced at a later date.