After a one-year absence, the S4 will return as a 2010 model. In place of the current car's 4.2 liter V8, the new S4 gets a 3-liter turbocharged V6 with direct fuel injection. Compared to the old V8, the new V6 produces slightly less horsepower (333 hp vs. the V8's 340) but more torque (325 lb-ft compared to 302 lb-ft). In fact, the new V6 produces more torque than the RS4's engine. Audi claims a 0-60 time of 5.1 seconds, 2/10ths faster than the current S4 and only one-third of a second behind the RS4. The bad news? The S4 will only be available as a sedan, not a wagon.