A practical family sedan or commuter car that turns into an open-road speedster for weekend fun, the 2001 Audi S4 has the extra power and punch for those who feel restricted by the A4. A 2.7-liter biturbo V6 engine hits 250-hp, matched with a standard 6-speed manual or optional 5-speed Tiptronic. Low-end torque starts around 1850 RPMs.