NEW GXP ENHANCES THE PERFORMANCE QUOTIENT OF THE '09 PONTIAC G8 LINEUP
06/09/2008
Pontiac
With the excellent handling traits of rear-wheel drive, the refined ride attributes of a four-wheel independent suspension and the exhilaration of available V-8 engine power, the Pontiac G8 lineup delivers the type of crisp driving experience typically found in more expensive performance sedans.
Introduced for the '08 model year, the G8 lineup's performance range expands in 2009 with the track-tuned GXP model. Motivated by a 6.2L LS3 V-8 that makes more than 400 horsepower (300 kW) and imbued with razor-sharp ride and handling traits, the GXP is the ultimate expression of Pontiac style and performance.
"The addition of the G8 GXP to the lineup proves Pontiac has never been more serious about the business of performance," said Susan Docherty, vice president of Buick-Pontiac-GMC. "More than just raw power, the GXP delivers the sophisticated yet exciting driving experience that enthusiasts expect in a car costing far more."
As the G8 joined Pontiac's lineup midway through the '08 model year, changes across the lineup are few but bring more standard technology to the table. They include XM Satellite Radio and Bluetooth capability on all models. Available later in the model year, Bluetooth capability is intergrated into the G8's standard OnStar system,enabling hands-free phone calls for safer, more convenient connections.
Additionally, four new colors are added to the G8's exterior palette: Maverick Silver Metallic, Sport Red Metallic, Stryker Blue Metallic and Pacific Slate Metallic. (Stealth Blue Metallic and Ignition Orange Metallic are discontinued.)
G8 lineup
G8 is the first North American application of GM's new global rear-wheel-drive architecture. The 2009 lineup comprises three models: G8, G8 GT and the new G8 GXP. Each delivers a broad range of standard performance, convenience and safety features, including:
Four-wheel independent suspension
Four-wheel vented disc brakes with ABS and traction control
StabiliTrak electronic stability control system
Seat-mounted thorax air bags and dual-stage frontal air bags for front passengers, with automatic passenger sensing system
Roof rail side-impact air bags for both seating rows
OnStar
XM Satellite Radio
Power-adjustable front seats
Fog lamps
Polished stainless steel exhaust tips
Low-profile rear lip spoiler
A sport package is available for G8 GT models; it adds features such as 19-inch aluminum wheels and performance tires; a leather-wrapped sport steering wheel and alloy pedals.
The G8's powertrains consist of a responsive V-6 engine in the base model and a 361-horsepower (268 kW) 6.0L V-8 engine for the GT. The new GXP packs a 6.2L V-8 that tops 400 horsepower (300 kW).
G8 GXP details
The G8 GXP takes the G8's responsive driving experience, refined passenger environment and aggressive good looks to a new level, with distinctive design cues, unique interior elements and a stirring driving experience. It is powered by a 6.2L V-8 (LS3) that produces an estimated 402 horsepower (300 kW)* and 402 lb.-ft. of torque (546 Nm)*. SAE-certified numbers will be announced later; please check media.gm.com for updates.
A Hydra-Matic 6L80 six-speed automatic is standard with the LS3 engine, and a six-speed Tremec TR6060 manual transmission is available. Both are engineered for robust, high-performance operation.
A 3.27 final drive ratio comes with automatic-equipped GXPs and a 3.70 gear is matched with the manual transmission. A limited-slip differential is standard. This powertrain combination delivers 0-to-60 mph performance of about 4.7 seconds, and a quarter-mile time of approximately 13.0 seconds at 108 mph.
The GXP's ride and handling was developed and validated on racetracks and highways around the world, including the famed Nürburgring racing circuit. It rewards the driver with sharp, immediate responses, as well as a well-balanced road feel during spirited driving.
A Brembo braking system matches the GXP's boost in performance with an equivalent increase in stopping power. The system includes 14-inch (355 mm) vented front and 12.76-inch (324 mm) rear disc rotors, with special quad-piston alloy calipers in front. The alloy calipers on the rear brakes have single-piston actuation. The four-wheel disc brake system includes standard anti-lock brakes and all-speed traction control.
The GXP rides on unique 19-inch polished aluminum wheels with a special machined face. Performance-oriented summer P245/40R19 tires are standard, and a comparable all-season tire is available. Combined with the suspension and steering enhancements, this setup gives the GXP exceptional cornering grip.
G8 design
All G8 models share a progressive styling package highlighted by strong Pontiac design cues, such as a dual-port grille, fog lamps, bold wheels and a confident, wheels-at-the-corners stance. The design accents the car's performance lineage, with fenders that flare over the wheels, seemingly hugging the wide tires and enhancing the sporty stance.
Distinctive elements include hood scoops and front fender vents, as well as projector-beam headlamps housed in crystal-clear lenses. At the rear, the taillamps feature bright detail work surrounding the red lighting elements. G8 models have red taillamp lenses and twin polished stainless steel exhaust outlets, while G8 GT models feature clear taillamp lenses and quad polished stainless steel exhaust tips. All models have an antenna mounted at the rear of the roof.
The G8 GXP has distinctive styling cues, including a unique front fascia with a lower splitter and a unique rear fascia diffuser.
G8 interior
Designed to meld form and function with world-class fit and finish, the G8's interior delivers both comfort and convenience, packaged in a level of sophistication not often found in its price range. A driver-oriented instrument cluster positions the gauges for easy, direct line of sight; an electronic driver information center is located between the large, round tachometer and speedometer.
Attention to detail includes easy-to-read instruments, selective use of satin and chrome trim and rich-feeling, grained textures throughout. The instrument cluster glows with crisp, white light on the primary instruments and Pontiac's signature red lighting illuminates the rest of the instrument panel cluster.
The seats offer firm support to hold occupants in place during aggressive cornering; all seats were designed to deliver excellent comfort during long drives. Cloth seating surfaces are standard, with heated leather seating available. G8 GT models also offer an optional two-tone cloth or leather combination that pairs black with red inserts and color-matched instrument faces on certain exterior color combinations.
GXP models also offer two-tone leather upholstery in black and red, with GXP-logo embroidery. The GXP interior also boasts alloy sport pedals as standard equipment.
G8 engines
The base G8 model receives a 3.6L DOHC V-6 with variable valve timing, rated at 256 horsepower (190 kW) and 248 lb.-ft of torque (335 Nm). Variable valve timing optimizes the power and efficiency across the rpm range, giving the car the best performance at all speeds.
The G8 GT is powered by a uniquely configured 6.0L small-block V-8, rated at 361 horsepower (268 kW) and 385 lb.-ft. of torque (520 Nm). It features GM's Active Fuel Management technology, which allows the engine to switch from V-8 power to four-cylinder operation during light-load driving conditions, enhancing fuel economy.
The GXP's 6.2L LS3 engine is the newest member of GM's small-block V-8 family. It features a revised, larger-bore cylinder block, high-flow, L92-style cylinder heads; larger-diameter pistons; unique camshaft and camshaft timing; revised valvetrain with offset intake rocker arms; high-flow intake manifold; and high-flow fuel injectors.
The LS3 engine has an aluminum cylinder block with cast-in-place iron cylinder liners. Larger bores help create a 376-cubic-inch displacement. The block casting also features revisions and machining in the bulkheads to enhance its strength and improve bay-to-bay breathing. New pistons were designed for high-rpm performance.
High-flow cylinder heads aid engine breathing and are based on the large port and valve design found on the LS7 engine and other GM L76 engines. The larger-capacity, straighter intake port-design optimizes intake flow to the combustion chamber, an effect augmented by large valves, measuring 2.16 inches (55 mm) on the intake side and 1.59 inches (40.4 mm) on the exhaust side.
Transmission choices
The base G8's 3.6L V-6 engine is paired with a five-speed automatic transmission with Driver Shift Control, offering a choice of balanced shift points, a performance-oriented Sport Mode or full manual control. This combination helps give the car solid fuel economy, with an EPA-rated highway rating of 25 mpg.
The GT and GXP's standard Hydra-Matic six-speed 6L80 automatic transmission is technologically advanced and robust. It uses a clutch-to-clutch operation and an integrated 32-bit transmission controller to deliver smooth and precise shifts. The six-speed has a generous 6.04:1 overall ratio that enables a "steep" first-gear. The result is strong launch acceleration along with "tall" overdrive ratios that lower engine rpms for better fuel economy and reduced noise. The 6L80 also features Driver Shift Control for increased driver control.
A six-speed Tremec TR6060 manual transmission is optional on the GXP. This next-generation manual smoothly transfers the engine's power and torque to the rear wheels with a reduction in shift throw. The transmission features a host of refinements including premium gear synchronizers; stronger gears, housing, and bell housing; a single-piece counter shaft; and machined gear teeth.
A limited-slip rear differential is standard with GT and GXP models.
G8 architecture
Built on GM's global rear-wheel-drive architecture, the G8 is designed to deliver world-class levels of strength and refinement, along with crisp driving dynamics. Among the architecture's design attributes is a layout that promotes a nearly 50/50 front-to-rear weight balance ratio, thanks to design features that include a steering rack mounted ahead of the front axle, engines mounted low and rearward in the front chassis cradle and a trunk-mounted battery.
GM's rear-drive architecture also has an exceptionally strong unitized chassis/body structure, including advanced-strength steel used in more than 80 percent of its construction. This strong foundation enables several factors than benefit the G8's driving experience, including smoother, more solid ride characteristics and more precise suspension tuning, as the stiffer structure allows engineers to tune the suspension without having to account for chassis flex.
The stiff structure also enhances safety, as it helps absorb crash energy through a multiple load path strategy that includes optimized front-end and rear-end deformation zones. (See safety section below.)
Responsive suspension systems
A unique, four-wheel independent, performance-tuned suspension system is integrated with the G8's structure, and is the result of eight years of development. It uses the strength of the body structure to enhance the driving experience through optimized steering, handling and driving control.
The G8 rides on a long, 114.8-inch (2,915 mm) wheelbase, with the wheels set wide on 62.7-inch (1,592 mm) front and 63.3-inch (1,608 mm) rear tracks. The front suspension features a multi-link, MacPherson strut design that incorporates a direct-acting stabilizer bar, while the rear suspension uses a four-link independent design, with progressive-rate coil springs over shocks and a decoupled stabilizer bar.
The front suspension uses a hydraulically damped bushing on the forward end of the tension link for improved ride isolation. The lateral link features a rubber spherical joint that enhances lateral stiffness. Camber, caster and toe are fully adjustable.
With the rear suspension, a high degree of lateral stiffness is achieved with the use of two lateral ball joints per side. A rubber-damped suspension frame further isolates the body structure from noise, vibration and road harshness.
The G8 sedan and GT models use the same FE2 suspension setup, balancing crisp responsiveness with a compliant ride that is suitable for everyday driving. The GXP move up to a track-tuned FE3 suspension designed to further enhance the car's cornering potential.
The steering rack is mounted forward of the front axle centerline - with dual lower links and individual ball joints at the outer ends - which enhances the balanced feel of the car while also contributing to a more direct steering feel. Steering rates are tuned specifically for each model, with the GXP's steering tuned for immediate response with increased driver feedback. All G8 models have a 37.4-foot (11.4-meter) turning circle.
Brake systems
A four-wheel disc brake system includes standard anti-lock and all-speed traction control features and is partnered with standard StabiliTrak electronic stability control system. Both the base and GT models feature vented front and rear disc rotors, with twin-piston alloy calipers in front; the rear brakes feature alloy calipers with single-piston actuation. The brakes are approximately one-inch larger on the higher-performance GT model.
The high-performance GXP receives a Brembo braking system that includes 14-inch (355 mm) vented front and 12.76-inch (324 mm) rear disc rotors, with special quad-piston alloy calipers in front.
Safety
Safety was one of the foremost goals in the design of the G8's architecture. It combines a sturdy, crash-absorbing body structure and state-of-the-art passenger protection technology. Examples of these elements include:
Efficient, energy-absorbing front structure and a strong occupant safety cage
Six standard air bags, including dual-stage frontal air bags, side thorax air bags for front-seat passengers and roof rail-mounted head curtain air bags for both seating rows
Multiple air bag sensors: two electronic front sensors and two side-impact sensors, all connected to a sensing diagnostic module
Front safety belts with load limiters and dual pretensioners
Ride-down steering column and breakaway pedal system
Four-wheel vented disc brakes with ABS
StabiliTrak electronic stability control system
All-speed traction control
Tire pressure monitoring system
OnStar (available Turn-by-Turn Navigation)
LATCH system (Lower Anchors and Top tethers for CHildren) for child safety seats