Substantially enhanced just last year, the five-passenger 2009 Cadillac STS full-size luxury sport sedan is primarily a carryover from last year. Equipped as either rear-wheel or all-wheel drive, the STS has a 3.6L V6 engine that produces 302 hp and 272 lb-ft of torque, while the 4.6L V8 engine makes 320 hp and 315 lb-ft of torque, and both engines come with a six-speed automatic transmission. Fuel mileage EPA estimates are good for 17 mpg city/26 mpg hwy and 20 mpg in combined driving for the V6 and 15/24/18 mpg for the V8. Cadillac STS safety features highlight antilock disc brakes, stability control and a full complement of airbags that include front-seat side and full-length side curtains. Available advanced technologies include a lane departure warning system that alerts drivers when they have strayed into another lane without signaling, a blind-zone alert system and active steering, available only on AWD V8 trims, which turns the front wheels into a skid when the rear wheels lose traction.