Audi R18 e-tron quattro grabs podium finish at its Spa-Francorchamps debut

The R18 e-tron quattro is a big deal for Audi as it is the first ever diesel hybrid vehicle that will enter the LeMans endurance racing series. Dr Wolfgang Ullrich, Head of Audi Motorsport, states that the R18 e-tron quattro has been arguably the most challenging project for Audi Sport. 

There are still five weeks to go for the 2012 Le Mans 24 hours endurance racing series to begin. But Audi was eager to test their revolutionary diesel hybrid R18 e-tron quattro, so they entered it in round two of the World Endurance Championship (WEC) at Spa. The two Audi R18 e-tron quattro cars that took part in the race finished second and fourth while first and third places were taken by two Audi R18 Ultras. 

The Quattro system on the R18 e-tron is the first to be powered by both an internal combustion engine and an electric motor. The rear axle is powered by a V6 turbo diesel engine while the front axle is powered by an electric motor. 

This means that unlike a traditional Quattro system there is no mechanical link between the front and rear wheels of the race car. The quattro system on the Audi R18 e-tron is completely electrical. The front axle has a mechanical energy recuperation system that feeds the energy into a flywheel energy storage system that powers the front wheels during acceleration.  

The decision to incorporate a flywheel based energy recuperation system instead of the traditional battery powered hybrids was considered to keep the R18 e-tron quattro as light as possible due to its racing characteristics. But, the new flywheel energy recuperation system is also considered for production vehicles as it reduces the added expense of a battery and its weight which hampers fuel economy of a hybrid. 

Dr Ullrich, stressed, "Right from the beginning of the project, we intensively liaised with our colleagues on the production side of the house where concepts are created and examined for future road vehicles. They worked out a solution in which one of the axles is driven by the power supplied by an internal combustion engine and the other by the power from an electric motor. This defines a new form of quattro drive - the e-tron quattro. We’re also pursuing this strategy in racing, which again puts us on the front row. Not only because we’ll be the first at Spa to contest a race with such a concept in an LMP race car, but because production development will be able to benefit from our system in the future as well." 

The base for creating the R18 e-tron quattro was the Audi R8 GT that underwent the first trials for a diesel hybrid. Dr Ullrich, says, "The implementation was possible, at relatively high levels of efficiency and we managed to package all the subsequent original components of the R18 e-tron quattro at the front end of the R8. That’s how our prototype for initial set-up and concept work was created."

Prior to the development of the R18 e-tron quattro, Audi made technological breakthroughs at LeMans first in 1999 with the first carbon fibre racing car, then the TFSI direct injection petrol engined race car for Le Mans, followed by the TDI engine project for Le Mans.