All the new models are powered by the same twin-turbo V8 engine with varying outputs of up to 513bhp which features Audi's fuel-saving cylinder-on-demand technology. This eight-cylinder unit replaces the naturally aspirated V10 FSI engine and improves economy by up to 25%.
The quartet of new S models will be open to order from next month, with first deliveries in July. The cars will cost from 53,995 for the S6, up to 77,900 for the range-topping S8.
The Audi S6 and S6 Avant: In the S6 and S6 Avant, the 4.0-litre twin-turbo engine produces 414bhp and can slingshot the S6 from 0-60mph in 4.6 seconds, while the Avant is just a tenth behind at 4.7 seconds. Top speed is limited to 155mph.
New systems include Audi's fuel-saving cylinder-on-demand technology, which shuts down four of the eight combustion chambers when demand is low during periods of motorway cruising, for example.
The downsized engine and new technology help to cut fuel consumption by up to 25% compared with the 5.2-litre V10. Average economy is now 29.4mpg for the S6 and 29.1mpg in the Avant.
Both the A6 and A6 Avant get a fast-shifting seven-speed S tronic gearbox, to transfer drive to the permanent four-wheel-drive system. This incorporates a sport differential, which allows variable torque distribution between the rear wheels.
The two new S models also get adaptive air suspension in its firmer Sport configuration, which lowers the body by 10mm. Both cars get 19-inch alloys and ventilated disc brakes; carbon-ceramic discs are an option.
Audi's Drive Select adaptive dynamics system which influences features such as throttle response, gearshifts, steering settings, power delivery, and air suspension performance is a standard fit on both variants. The driver can adjust the operation of these systems in five stages.
Both variants get Audi's active noise cancellation system, which broadcasts 'antiphase' sound via four cabin-mounted speakers to cancel out external noise that makes its way into the cabin.
The car gets a sporty appearance, too, with a front grille with chromed horizontal double bars. Another chrome strip adorns the front bumper, along with xenon headlamps with LED daytime running lights, and LED rear lights. The saloon gets a boot spoiler the Avant gets one on the roof while both get four elliptical chrome tailpipes.
Audi S7 Sportback: In the S7 Sportback, the new 414bhp 4.0-litre TFSI blasts the Audi from 0-62mph in 4.7 seconds, and on to a limited top speed of 155mph. The eight-cylinder unit uses Audi's cylinder-on-demand technology, which helps it achieve an average economy of 29.4mpg.
Delivery of power is taken care of by a seven-speed S tronic transmission, while the all-wheel-drive system has a sport differential acting on the rear wheels.
The S7 Sportback also has adaptive air suspension and the Audi Drive Select dynamics system.
Behind the 19-inch alloys are large, internally ventilated disc brakes front and rear. Their black calipers are stamped with S7 logos at the front. Carbonfibre-ceramic discs are available as an option. Other options include 21-inch alloys and dynamic steering, which varies adjust steering responses as speed increases.
Audi's active noise-cancellation system is also found on the S7.
Audi S8: The range-topping Audi S8 gets a 513bhp version of 4.0-litre engine. This propels it from 0-62mph in just 4.2 seconds, while top speed is electronically capped at 155mph.
Average economy for V8 is an impressive 28.0mpg, with CO2 emissions of 235g/km. This compares with the previous car's 5.2-litre V10, which recorded an average economy 21.4mpg in the equivalent test. This improvement of 6.6mpg is achieved despite a 69bhp increase in power. Cylinder-on-demand technology is also standard.
Power is transferred to the wheels through an eight-speed tiptronic transmission. The drivetrain includes a self-locking central differential, with a sport diff on the rear axle. During enthusiastic driving, this diverts the majority of the power to the outside wheels, which helps push the car through corners.
Like the other S models, the S8 also gets Audi's active noise-cancellation system as standard.
The S8's dynamics are aided by adaptive air suspension with variable damping, which can vary the ride height. This complements the dynamic steering, which uses virtually imperceptible corrections to stabilise handling when cornering on the limit. The all-wheel-drive system is also enhanced, as in the S6 and S7, by the sport differential that manages torque distribution between the rear wheels.
The S8 comes on 20-inch alloys, with 400mm disc brakes at the front and 365mm of stopping power at the rear. The matt black calipers up front are stamped with S8 logos. There's also the option of lighter carbonfibre ceramic discs.
Order books for the S6, S6 Avant, S7 Sportback and S8 open next month, with deliveries expected in July.
S6 saloon - 53,995
S6 Avant - 56,050
S7 Sportback - 61,995
S8 - 77,900