Prices will start from just over £34k when it goes on sale in April next year. The S4 will come in both saloon and estate versions producing 329bhp from the 3.0-litre V6 engine.
The S4 saloon will cost £34,225, more than £1k cheaper than its nearest rival, the BMW 335i M Sport. The Audi S4 Avant will cost £35,570.
Customers will also be able to specify a new seven-speed twin-clutch DSG transmission, which costs an additional £1420 in the saloon and £1230 in the estate.