Audi RS 5 Presentation: Top Model with Plug-in Hybrid and Torque Vectoring

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BMW and Mercedes have set the pace, and now Audi is catching up again. The power struggle between these three has a long tradition. In the current iteration of the M3 and M4, BMW relies on a powerful six-cylinder engine with up to 390 kW. Mercedes is trying a plug-in hybrid that uses a four-cylinder engine. Despite a system output of 500 kW, my colleague Clemens Gleich was not convinced after testing this concept. Audi is attempting a middle ground, and is taking an elaborate approach to power distribution.

Drive

The combustion engine is a 2.9-liter V6 with two turbochargers, which already throws 375 kW and 600 Nm into the ring. The electric motor, housed in the eight-speed transmission, contributes 130 kW and 460 Nm. Together, the driver can access 470 kW and 825 Nm of torque. The manufacturer claims 3.6 seconds in the standard sprint and a top speed of 250 km/h. For an additional charge, the top speed can be increased to up to 285 km/h.

With the Miller cycle, where the intake valves close earlier than usual, the V6 is intended to operate more efficiently in partial load operation. Compared to its predecessor, the injection pressure has also been increased, Audi writes, without providing specific figures. In WLTP with a discharged battery, 9.5 to 10.2 liters are stated. We assume that Audi has prepared the powertrain and the car for the Euro 7 emissions standard.

No DC Charging Possible

The electric motor is designed as an external rotor. The rotor rotates around a stationary stator. Audi promises advantages in terms of efficiency, torque, and cooling. The electric motor draws power from a traction battery with 22 kWh net. In WLTP, this is sufficient for up to 84 km. As with other plug-in hybrids based on the A5, charging is only possible with three-phase AC power at 11 kW. DC charging is possible in other plug-in hybrids of the group, including models from Audi.

All three manufacturers mentioned at the beginning distribute such high power to all four wheels in their top models. In the RS 5, a self-locking center differential sits behind the eight-speed transmission. This variablely distributes the torque between the front and rear axles depending on the driving situation – from 70 percent front and 30 percent rear to a maximum of 15 percent front and 85 percent rear.

Active Torque Vectoring

In addition, there is an active torque-vectoring system on the rear axle, which Audi describes with an electromechanical superposition gearbox. An actuator, designed as a synchronous machine with a power consumption of 8 kW and 40 Nm in the rear differential, can distribute up to 2000 Nm variably between the rear wheels with an appropriate gear ratio at the wheel. This allows, for example, a steering effect to be generated by providing more torque to the outer wheel in a curve.

Unlike purely mechanical systems, the actuator is not limited in the direction of torque. If the situation requires it, it could even be used for recuperation. Whether Audi also makes use of this is left open by the press release. This is very unlikely, as they have entirely different options via the electric motor in the transmission.

More Than 100,000 Euros

The RS 5 can be ordered this quarter, with deliveries expected to begin in the summer. Audi charges 106,200 Euros for the sedan, and the station wagon will be offered from 107,850 Euros. For comparison, a BMW M3 with all-wheel drive starts at 107,600 Euros, and the Mercedes-AMG C 63 S E starts at 115,472 Euros.

(mfz)