Audi set for corrected fuel allowance post-Le Mans

The decision has been made after a small miscalculation was discovered in the Equivalence of Technology formula, which is used to limit the gap in performance between the different hybrid LMP1 entries.

“We will get a little bit more [fuel] because there was a calculation issue between 6 and 8MJ, and it has now been corrected in our favour, but it is not a big amount,” Audi’s Head of Engine Technology Ulrich Baretzky confirmed.

Theoretically, in the regulations, an 8MJ petrol engine is treated the same as a 6MJ diesel engine, but Audi runs only one recuperation system - because it cannot afford to run a second one due to the weight of the engine.

For balance, the ACO and the FIA weigh the complete powertrain, and define the difference between the two units, which is believed to be approximately 30-35kg.

With the diesel being a higher weight, it doesn’t therefore have the opportunity to step up to 8MJ and thus something called the K-Factor (one element of the equation of how energy is calculated per sub-class) balances the weight of the diesel unit against the gasoline unit.

The incentive to the manufacturers was laid out in the regulations: that the higher the energy retrieval class you go, a gain of half a second per MJ is registered.

It was agreed by the LMP1 manufacturers that to go to the highest current workable sub-class of 8MJ, the cars would be able to do 14 laps at Le Mans on fuel. But, Audi cannot on the current fuel allocation achieve 14 laps, while the others can.

Confirmation of Audi’s corrected fuel allowance is set to be announced in the coming days at Le Mans.

Motorsport.com also understands that the proposed 2018 regulations will not be released wholesale, but aspects of what has so far been agreed will be made public at the annual ACO Press Conference on Thursday morning.