2010 Audi S4

Audi’s performance version of the excellent A4 is coming stateside in September 2009, about six months after the Europeans first get to snap it up. But everyone will get their first official look at the S4 and S4 Avant at the same time: in October at the 2008 Paris auto show. In the case of the S4 Avant, U.S. residents shouldn’t get too attached—unlike the last generation, we won’t get it here.

Key to the new S models is the redesigned 3.0-liter TFSI (supercharged) V-6 that generates 333 horsepower, replacing the 4.2-liter V-8 of the past. Horsepower is down slightly from 340 with the V-8, but the new engine makes up for it with 325 lb-ft of torque.

Audi claims the new engine will propel the sedan from 0 to 62 mph in 5.1 seconds and the wagon will do the dash in 5.2 seconds. Top speed is 155 mph. Channeling the power is Audi’s latest dual-clutch S tronic automated manual transmission, designed for quick and seamless shifts—this time with seven forward speeds instead of six. Shifts are accomplished either completely automatically, or via paddles or the shift lever. A six-speed manual is standard.

Torque is distributed between the rear wheels via a new “active sport differential” designed to combat understeer or oversteer by directing virtually all power to the outer rear wheel when needed. The differential is positioned in front of the clutch, allowing Audi to push the engine six inches forward and even out the axle loads, which the automaker says will increase stability as a result. We’ll get back to you after we’ve had some seat time.

The German automaker says it prefers the combination of gasoline direct injection and supercharging for the new V-6, as opposed to going the twin-charger (both super- and turbocharged) route, saying the choice is superior “both in terms of packaging and of starting performance and responsiveness.” The other benefit is fuel economy: Audi says the S4 will average 24 mpg.