We're eagerly awaiting the chance to see the S lineup in Frankfurt but, in the meantime, Audi has released new details about the twin-turbo 4.0-liter V8 engine.
Jointly developed with Bentley, the aluminum-intensive mill has classic 90 degree cylinder banks, a charge-air intercooler and an advanced exhaust system. These are nice touches, but the real story is "cylinder on demand" technology which deactivates four-cylinders when maximum performance isn't required. Audi estimates this improves fuel efficiency by up to 5%, while reducing emissions 10 to 12 g/km. If that isn't impressive enough, there's also a start/stop system which cuts CO2 emissions by as much as 24 g/km.
To reduce NVH (noise, vibration and harshness), the engine sits on active mounts which detect vibrations and uses a counter-vibration to limit engine movement. Likewise, the active noise control system uses four microphones to detect "disturbing constituents" in the cabin and eliminate them by sending an opposing sound through the speakers.
As we have previously reported, the engine develops 420 PS (309 kW / 414 hp) and 550 Nm (406 lb-ft) of torque in the S6 and S7. It enables the cars to accelerate from 0-100 km/h in 4.8 and 4.9 seconds, respectively.
The S8, other the other hand, boasts 520 PS (382 kW / 513 hp) and 650 Nm of torque (479 lb-ft) of torque. This allows the car to rocket from 0-100 km/h in 4.2 seconds, before hitting an electronically limited 250 km/h (155 mph).
Check out the press release for additional information