Porsche's family of rear-engine 911 sport cars is now available in three power levels for 2008--standard, S, and Turbo--and in three body styles--Coupe, Targa, and Cabriolet. The standard engine on the 911 is a 325-horsepower, 3.6L horizontally opposed six-cylinder engine. S models get a 355-horsepower, 3.8L flat-six. A six-speed manual gearbox is standard, but a five-speed automatic transmission is available throughout the model line and allows "Tiptronic S" manual gear selection. The unique Targa, introduced last year, features a panoramic roof system that provides a completely open roof when desired, combined with the safety and convenience of a coupe for when the weather turns unpleasant. The Targa also has hatchback-style access to the cargo area with its pop-up back window and is the only 911 model with a separately opening lower tailgate. This body style is not available as a Turbo. There are also several all-wheel-drive variants of the 911. The Carrera 4 and 4S Coupe and Cabriolet models, along with the Targa 4 and 4S, get larger wheels and tires and a widened track for a more aggressive appearance in addition to the all-wheel drive system, which can send between 5 and 40 percent of engine torque to the front wheels. As standard equipment on Turbo models and available elsewhere in the line, the Porsche Active Suspension Management (PASM) system adjusts damper stiffness almost instantaneously for the driving conditions and works in conjunction with the stability control system. Cabriolet models get a tight, three-layer soft top that can be opened or closed in about 20 seconds, plus pop-up rollover bars behind the rear seats for supplemental safety and a specially calibrated suspension. Variable-ratio steering is standard on all 911 models. S models come with PASM technology standard, while it is optional on the non-S models. Even though the 911 is primarily a sports car, it comes equipped with many of the features that might be expected in a luxury coupe, like automatic climate control, a 235-watt, nine-speaker sound system, power accessories, heated mirrors and windshield nozzles, and a trip computer. Split-folding rear 2+2 seatbacks allow for an expanded cargo area, and there's also a substantial cargo area in front. The options list is long, including various wheels and trim upgrades; other highlights include the Sport Chrono Plus package, which brings a more aggressive throttle calibration and a built-in lap timer, and a DVD-based navigation system. The top 911 Turbo and new-for-2008 Turbo Cabriolet come with a twin-turbocharged, 3.6L flat six-cylinder engine. The engine makes 480 horsepower, 60 more than its predecessor, and 460 lb-ft of torque, also up significantly. With the optional Sport Chrono Package, the turbocharger is allowed a 10-second "overboost" that brings peak torque to 505 lb-ft for quick bursts of passing. The Turbo can go from 0 to 60 in only 3.7 seconds and on to a top speed of 193 miles per hour. The Turbo Cabriolet can get to 60 mph in just four seconds. Also new for 2008 is the 530-horsepower, very limited-edition GT2, which brings a special Le Mans race-car-inspired body and prominent rear wing, along with weight savings throughout for a top speed of 205 mph, and ranks as the most expensive 911 model ever. The track-oriented GT3 returns for 2008, and it is accompanied by the GT3 RS. Both feature a 415-horsepower, non-turbocharged version of the 3.6L flat-six with a high 7,600-rpm redline. The GT3s are only offered with a six-speed manual transmission with shorter gear ratios. The GT3 duo comes with rear-wheel drive and includes a traction control system that can be completely disabled, along with a mechanical limited-slip differential to help send the power to the wheels as needed. PASM is standard, and the GT3 has a normal mode for driving on rougher surfaces and a sport mode for maximum racetrack performance.