Like the regular A5, the S5 Sportback will be longer and lighter than today's car, which tips the scales at 2375kg, thanks to weight-saving measures applied from the A4. A switch to five-link suspension is also expected.
While the regular A5 Sportback will share its engine range with the latest A4, the S5 model will use the S4's new 3.0-litre V6 turbocharged petrol motor. In the S4, that engine produces 349bhp and 369lb ft of torque, and similar figures are expected in the S5 Sportback.
The new engine, coupled with the S5's lightweight components and linked to an S tronic automatic transmission, should allow the new S5 Sportback to eclipse the current version's 0-62mph sprint time of 5.4sec. The current S5 Sportback has a supercharged 3.0-litre V6 petrol with 328bhp and 325lb ft of torque.