Audi is introducing the third-generation RS 4 Avant, a modern classic model from the automaker that combines high performance with great everyday practicality. It is fitted with a 4.2-liter V8 powerplant that generates 331 kW (450 hp) at 8,250 rpm for a specific output of 108.1 hp per liter. This engine is the same normally aspirated and high-revving V8 engine that runs the RS 5 Coupe. The Audi RS 4 Avant is scheduled to be delivered starting in fall this year in Germany, costing as low as €76,600.
From 4,000 to 6,000 rpm, the engine achieves its maximum torque of 430 Nm (317.15 lb-ft). The 4,163 cc engine enables the RS 4 Avant to accelerate to 100 km/h (62.14 mph) from a standstill in 4.7 seconds with a top speed of 250 km/h (155.34 mph).
Top speed of up to 280 km/h (173.98 mph) is also available upon request. The 4.2 FSI engine is hand-built at the automaker's Györ facility in Hungary. It boasts of having excellent efficiency, consuming not more than 11 liters of fuel per 100 km (21.38 U.S. mpg) on average. With the long top gear and high efficiency, the standard seven-speed S tronic is also responsible for the automobile's exemplary fuel economy.
Drivers can enable the dual-clutch lightning-fast transmission shift automatically or change gears manually with the selector lever or the paddles found on the steering wheel. Drivers can also activate the Launch Control to obtain an explosive start. This control manages the engagement of the clutch at a minimum wheel slip and an optimum starting speed.
In its latest evolutionary stage, the quattro powertrain features the self-locking crown gear center differential and torque vectoring. The two crown gears rotating inside the center differential get their name from their tooth geometry.
The front crown gear acts on the output shaft to the front axle differential, the rear gear on the prop shaft to the rear axle differential. A lightweight plug construction provides the connection. The crown gears mesh with four rotatable pinion gears. They are arranged at right angles to each other and are driven by the differential's housing, i.e. by the transmission output shaft.
Under normal driving conditions, the two crown gears rotate at the same speed as the housing. Because of their special geometry, they have specifically unequal lever effects. Normally 60 percent of the engine torque goes to the rear differential and 40 percent to the front differential.
If the torques change because one axle loses grip, different speeds and axial forces occur inside the differential, and the integrated plate packages are pressed together. The resulting self-locking effect now diverts the majority of the torque to the axle with the better traction; up to 85 percent can flow to the back. If the rear axle has less traction, up to 70 percent of the torque flows to the front axle.
With this extremely broad torque distribution range, the crown-gear center differential surpasses its predecessors. Forces are redistributed without any time lag and absolutely consistently. The mechanical operating principle guarantees maximum efficiency and immediate response. Other strong points of the crown-gear differential are its compactness and low weight - at 4.8 kilograms (10.58 lb) it weighs roughly two kilograms (4.41 lb) less than the previous unit.