The S4 is outfitted with a 4.2-liter V8 engine that generates 340 horsepower. A standard six-speed manual transmission and Audi's quattro all-wheel drive system transfer power to the ground; a six-speed Tiptronic automatic transmission that allows manual gear selection is optional. The S4 comes with 18-inch alloy wheels and performance tires, bi-xenon headlights, leather sport seats, aluminum trim elements and satellite radio. New for 2009, Bluetooth wireless connectivity is now standard equipment. For 2009, the Audi S4 remains on the previous-generation A4 platform, with minimal changes, and is available in a Cabriolet model only.