The drivetrain in the Audi RS 7 Sportback delivers the power to the road with aplomb. The eight-speed tiptronic impresses with particularly short shift times and gentle, almost imperceptible gear changes. A classic torque converter transmission, it offers D and S modes. Drivers wishing to change gears on their own can use the shift paddles on the steering wheel or the selector lever bearing a unique RS design. Another function, Launch Control, delivers the engine's power to the road with defined tire slip and maximum traction.
The eight-speed tiptronic, which is integrated into the engine's thermal management system, plays a major role in the efficiency of the Audi RS 7 Sportback. Its lower gears are closely spaced for sporty response while the top gear is tall to reduce fuel consumption. The spread of 7.1:1 is very wide. The Audi RS 7 Sportback accelerates powerfully from a standing start and operates at relatively low rpm even in eighth gear. The torque converter lockup clutch connects the gearbox directly to the engine in most driving situations, thus further increasing efficiency.
The heart of the quattro drivetrain is a newly developed center differential that can widely vary the distribution of torque. In normal driving, the purely mechanical differential sends 40 percent of the engine's power to the front axle and 60 percent to the rear axle. When required, it can immediately distribute up to 70 percent of the torque to the front, or up to 85 percent to the rear. Yet another strength of this new differential, whose temperature is modulated by a dedicated oil cooler, lies in its low weight. Indeed, it weighs 1.8 kilograms (3.97 lb) less than the previous generation.
The center differential works closely with the torque vectoring. When the latter detects that the wheels on the inside of the curve, which are under a reduced load, are about to slip, it brakes these wheels ever so slightly by applying the pads to the discs with minimal pressure. This makes handling at the limit even more neutral and safe. If the electronic stabilization control (ESC) has to intervene at all, it does so later and more gently.
Even more dynamic: the sport differential
Audi offers another component for the quattro drivetrain as an option. The sport differential actively distributes torque between the rear wheels. When turning into or accelerating in a curve, it sends the majority of the torque to the outside wheel and pushes the RS 7 Sportback into the curve, nipping any tendency to oversteer or understeer in the bud. The driver can precisely control the function of the sport differential via the Audi drive select dynamics system.
The sport differential is an extension of the classic rear differential. It has a superposition gear on both sides that turns ten percent faster than the drive shaft. An electrohydraulically actuated, multi-plate clutch provides the connection between the shaft and the superposition stage. When the clutch closes, it steplessly imposes the higher speed of the superposition gear on the outside wheel. The additional torque required is drawn away from the inside wheel.
The equipment and data specified in this document refer to the model range offered in Germany. Subject to change without notice; errors and omissions excepted.