Our testing reveals the S5 ragtop is just half a second slower -- or less quick -- from 0-60 mph than the V-8 Mercedes-Benz SLK55 AMG and V-8 S5 coupe. In the quarter mile, it's 0.8 second slower than the Benz, 0.5 slower than the S5 hardtop. The Cabriolet's new engine seems poised for the new CAFE order, with 17/26 mpg EPA numbers, versus 16/24 for the S5 V-8 coupe with the S tronic and 14/22 for the manual coupe. (The S4 sedan with the supercharged 3.0 gets 18/27 mpg with the manual; 18/28 with S tronic.) Engine downsizing, even among expensive German performance cars, is the Next Big Thing, and Audi has trumped BMW, which is going back to a six-cylinder engine for the next M3.
The 3.0 TFSI features gas direct injection and the intercooled supercharger -- "T" typically means "turbocharged" in VW and Audi engines, but apparently SFSI doesn't seem sporty enough. While its sound is distinctively blown-V-6, Audi has tuned it to sound the part of a V-8 killer, but with a higher pitch. The brappy soundtrack is accentuated by back-pressure burbles during upshifts of the seven-speed S tronic dual-clutch transmission, when you get aggressive with the throttle.