The most striking feature of the 2009 Sierra is the interior. The cabin offered on the top SLT trim is similar to that currently offered on GM's full-size sport-utility vehicles such as the GMC Yukon, and offers standard luxury features like power heated front leather seats, six-disc CD/MP3-capable audio system and heated windshield washers, while top crew cab SLT models add rain-sensing wipers and a rear-seat audio system. SLT models are further differentiated by a completely different instrument panel and door panels, a huge, 20.1-liter center console storage area, and upgraded five-liter glove box. Ultrasonic rear parking assist is available. The work truck and SL trims are equipped for those who plan to use their pickup for utility, with a more basic interior treatment. These trims still feature larger control knobs, plus a lockable in-seat storage bin that's large enough for a laptop computer and has a built-in 12-volt power outlet. The SL adds most popular equipment like air conditioning, cruise control, and a CD/MP3 audio system, and a SLE convenience package brings more luxury in the way of dual-zone climate control, a remote starting system and steering-wheel audio controls. Stadium-style rear seats, which are split 60/40 and have a fold-down center armrest, are standard on the crew cab and available on the extended cab. Rear legroom is sizeable on extended cab models and ingress and egress are easy thanks to rear access doors that open 170 degrees. Each trim level is available in either 2WD or an on-demand 4WD system with locking rear differential. A 195-horsepower, 4.3L V6 is standard on WT regular cab and 2WD extended cab models, while a 295-horsepower, 4.8L V8 is standard on WT 4WD extended cab, SLE regular cab and extended cab models, and WT and SLE crew cab models. A 315-horsepower, 5.3L V8 with Active Fuel Management, a system that automatically shuts down half of the cylinders during light-load driving, is available on the crew cab. The Sierra hybrid utilizes a 6.0L V8 engine linked to a continuously variable transmission (CVT) to product a total of 332 hp. It is a full hybrid, meaning it is able to run on both gasoline or solely on electric power, depending on load demands. The engine uses active fuel management to shut off cylinders when they aren't needed. Towing capacity is rated at 6,400 lbs. That 5.3L V8 is available as an option on all other models, while there's also a Flex-Fuel version that adds E85 compatibility. Thanks to Active Fuel Management, the 5.3L gasoline Sierra is rated at 16 city, 21 highway, the same as the base 4.3L V6 and one of the best figures in its class. As part of the maximum trailering package, a 367-horsepower (and 375 lb-ft), 6.0L V8 is available on SLE and SLT extended and crew cab models. This engine has variable valve timing and Active Fuel Management to maximize power output and efficiency. The package also includes a heavy-duty rear axle, locking differential, heavy-duty cooling system and high-capacity transmission. New this year is an optional 403-hp, 6.2L Vortec V8 -- the most powerful engine in its class. While a 4-speed automatic is standard, a new 6-speed is also available. Each of the five suspension systems available on the Sierra are tailored for particular driving situations, and each has a completely different character. The Z83 delivers the best ride, while the Z85 upgrades for improved handling and towing capacity. The Z71 is the option for those who plan to take their Sierra off-road, and for those wanting optimized street performance there's the Z60, which includes 20-inch wheels. The Sierra rides on a fully boxed frame with coil-over-shock front suspension and rack-and-pinion steering unit. StabiliTrak continues to be available on the Sierra. Cargo bed lengths are 5'-8" for the short bed, 6'-6" for the standard bed, and 8' for the long bed, and rated payload goes up to 2,160 pounds when properly equipped. One year of GM's OnStar system is standard on all Sierras, including automatic crash notification and a one-year subscription to the Safe & Sound plan.