Cons :
- Too much power to put through the front wheels.
- Black plastic look all over the interior.
- No manual transmission available.
- Understeer at the limit.
- Rear headroom may annoy tall passengers.
Interior :
Press Coverage :
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.
Product highlights of the Grand Prix GXP include a 5300 V-8 engine with Displacement on Demand technology, 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 available 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 “engine-turned metal” look and also wears the GXP logo.
The heart of the Grand Prix GXP is the new 5300 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 5300 V-8 produces a peak of 303 horsepower and 323 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 5.3L V-8 (LH6) engine.
With the 5300 V-8, 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.
The all-aluminum 5300 V-8 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.
Complementing the torque and horsepower of the 5300 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.
General Motors
With 63.4 percent of its weight squatting on its front tires (there's a large chunk of V-8 powertrain atop them), the Pontiac's front rubber needs to supply that same 63.4 percentage of the GXP's total lateral grip to negotiate curves.
The unsatisfying way to trace the turn would be to just crank in extra steering and flog the front tires into their 63.4 obligation, twisting in earplugs to endure the sickening understeer. Another would be for its designers to subtly increase the front tire's size, lessening their contact patch's pressure. It's a peculiarity of tires that the effectiveness of a tire's footprint increases with shoe size (lowering contact patch pressure is precisely the reason why racing cars always fit the biggest permissible rubber). Any wonder then that the GXP wears 255/45R18 fronts and 225/50R18 rears?
Motor Trend
I found it very easy to get in and out of the Grand Prix GXP and to get comfortable, though a friend who is over 6 feet tall found front seat ingress to be tricky, but found the nearly 90 degree opening rear door helped getting into the back seats. He also found head and legroom to be suitable in the rear for his frame. The driver-side seat is a six-way power unit with power lumbar control while the passenger gets to do everything manually. Both seats are heated.
The Heads Up Display (HUD) unit seems like a frivolous item, but I found myself enjoying the digital display, especially for the XM Radio station display. When the GXP is put into TAPShift mode, the speedo display gets smaller and the HUD broadcasts what gear you’re in.
If I had a gripe about the interior it would be an overabundance of gray. A little silver or carbon fiber accent could give the center stack less of a drab look. The HVAC control was easy to use and the Driver Information Center has many settings, though the control buttons are not all that attractive on the center stack. This GXP had the standard CD player with 6 speakers and I would suggest upgrading to the 6 disc with 9 speakers and an amp. It’s not hard to max out the capabilities of the base system if you really like to blast music. The GXP comes standard with a year of OnStar and side curtain airbags are optional.
Autoblog
History:
2002-2005 BMW 330i
2,979 cc / 225 hp / 221 lb-ft / 3285-3362 lbs / 0-60 mph 6.2 sec.
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