On sale in July 1989, Audi's new high-performance luxury "flagship" sedan challenged such logical rivals as BMW, Mercedes-Benz, and Jaguar. Exterior styling resembled Audi's 100/200 series, but only the front and front doors were shared with those models. Priced at a hefty $47,450, the V8 Quattro held a 240-horsepower, 3.6-liter aluminum V8 engine with dual overhead camshafts and four valves per cylinder. Power went through a 4-speed overdrive automatic transmission to a permanently engaged all-wheel-drive (AWD) system. Normally, engine output was split 50/50 between front and rear axles. When wheel slippage was detected, extra power would be sent to the axle with the greatest amount of traction, giving the best possible chance of getting underway properly. In extreme situations, all the power could temporarily go to either the front or rear, wherever it was most needed. This was the first Audi Quattro model with an automatic transmission, fitted with three modes: E for higher fuel economy; S for sportier performance; and M for manual operation. An automatic shift lock required that the brake pedal be applied to shift into a drive gear. Standard features included a driver's airbag, antilock brakes, 2-sided galvanized steel body panels, leather upholstery, a Bose sound system, and a cellular phone.