Three trim levels are available for 2009: the base SLE (or SLE1), SLT1, or the top-of-the-line SLT2. Just as for 2008, all trims are powered by a 3.6L DOHC V6 direct-injection engine that makes 288 horsepower (up from 275), and 270 pound-feet of torque, which is spread over a broad rpm range. All engines run through a 6-speed automatic transmission. Configurations with either front- or all-wheel drive are available. The all-wheel-drive system is oriented toward on-road driving and always delivers some torque to the rear wheels, applying more when needed for best traction. The system automatically varies the torque split from 90 front/10 rear to as much as 35/65 when needed for road conditions. The 2009 Acadia has a uni-body construction, which is lighter than body-on-frame and allows for better handling and comfort. With a 4-wheel independent suspension--including a space-saving rear-mounted system that helps isolate noise and vibration--the Acadia also has a low center of gravity to give it even sharper handling. Safety features include 4-wheel anti-lock brakes, traction control, antiskid system, front side airbags and side curtain airbags for outboard occupants in all three rows. GM's StabiliTrak® stability control system, with rollover mitigation technology, is also standard on the Acadia. The National Highway Traffic Safety Administration gives the 2009 GMC Acadia five of five stars for crashes involving the driver, passenger, side-impact front and side-impact rear. The Acadia comes in either 7- or 8-passenger interior configurations. Each setup has bucket seats in front and a three-passenger, 60/40-split folding third row. The 7-passenger version has two captain's chairs in the second row, while the 8-passenger version has a 3-passenger, 60/40-split bench seat for the second row instead. Both come with a second-row Smart Slide function, where the second-row seat cushion flips up and the seatback slides forward for easier access to the third row. Both the second- and third-row seats fold flat for mixes of the two. Cargo capacity is almost 117 cubic feet with all seats down, and 24 cubic feet behind the third-row seat if all are raised. The 2009 Acadia features a towing capacity of 4,500 pounds when properly equipped. Standard on the SLE are dual exhaust with chrome tips, tire pressure monitoring system, StabiliTrak®, 18-inch alloy wheels, 8-passenger seating, front and rear air-conditioning, full power accessories, cruise control, and a 6-speaker CD/MP3 stereo system with satellite radio. The SLT-1 comes standard with 8-passenger seating, heated mirrors with integrated turn signals, a Bose premium 10-speaker stereo system, 6-CD changer, driver information center, heated power front seats, and tri-zone automatic power control. Options packages add heated mirrors with integrated turn signals, leather seating with heated power front seats, second-row captain's chairs, triple-zone automatic climate control, Bluetooth connectivity and a Bose 10-speaker audio system with steering-wheel-mounted audio controls and a 6-CD changer. The SLT-2 adds a standard remote vehicle start, rear park assist, a power rear lift gate, power lumbar supports for the front seats, a 115-volt power outlet, washer nozzles and heated windshield. The Cargo package, with cargo shade and cargo net and the Convenience Package with remote start and Ultrasonic Remote Parking Assist are optional on all trims. Other options available include a rear-seat entertainment system, 19-inch aluminum wheels, heads-up display, touch-screen navigation and radio, and a "skyscape" dual sunroof with a large tilt and slide front panel with a fixed rear glass skylight. OnStar 8.0 is available with Turn-by-Turn Navigation and Destination Download that automatically downloads requested directions to the Acadia's navigation system.