The front-wheel-drive 2007 Pontiac Grand Prix sedan is available in three different models, each with its own powertrain. The base Grand Prix has a 200-horsepower, 3.8L V6 underhood, while the Grand Prix GT upgrades to a supercharged version of the V6 worth 260 horsepower, along with more high-performance equipment. The top GXP model stuffs a 303-horsepower, 5.3L V8 underhood. All models come with a four-speed automatic transmission. The top GXP comes with a standard head-up display (HUD), which projects dashboard displays onto the windshield. The system is designed to enhance safety, but the system can be switched off if not desired. A performance-tuned suspension, 18-inch forged aluminum wheels with W-rated tires, StabiliTrak stability control, and the Magnasteer II variable-assist power steering system are all standard on the GXP, which translates to a sportier overall driving experience. The GXP can accelerate from 0-60 in only 5.6 seconds, and its transmission features a TAPshift manual-shift function. All Grand Prix models have quite impressive fuel economy ratings. The base Grand Prix is rated at 30 mpg highway, and the V8 manages to get 18 city, 27 highway, thanks to Active Fuel Management, which helps improve fuel economy during light-load cruising and idling. A Special Edition Package adds a high-performance appearance to the base or GT models, including an air dam, rear spoiler, body-color grille, and dual bright exhaust tips. The Grand Prix has an especially spacious interior, including a back seat capable of carrying three adults. The back seats are split 60/40 and can fold forward or have a pass through for narrow objects like skis for objects as long as nine feet. All three Grand Prix models have four-wheel disc brakes, but anti-lock is optional on the base Grand Prix. Front and rear side curtain air bags are optional on all models. The OnStar system that's standard now includes GM's Advanced Automatic Crash Notification (AACN) system, which can make crash data available to 911 dispatch, depending on the situation. The service can also accommodate an optional Turn-by-Turn Navigation system.