Even though Porsche has yet to embrace Audi's turbo diesel, or green fuel approach, it was also attracted to the ALMS because the series encourages efficiency in performance and fuel use. Dr Frank-Steffen Walliser is Porsche's general manager of motorsport strategy and Dr Thomas Laudenbach is in charge of powertrain development in Porsche's motorsports department. The pair of engineers work closely together on Porsche's racing programmes.
"I think, for sports car racing in particular, and racing in general, it's important to be relevant," Walliser said. "For me, sports car racing offers from history everything that is necessary for such a formula. We see sports car racing as the right place for us. We don't have to invent new rules or new ideas to attract us. Everything is there. For us, it's the perfect playing ground and proving ground.
"The current ACO rules allow different engines - V8s, V12s, V10s, turbos, normally-aspirated engines," Walliser continued. "They added different fuels, including diesel and gasoline. The ALMS series has already added a third fuel, an ethanol blend starting with E10 and perhaps, in the future, going to E55, or whatever. So, in comparison to other racing series, we have different concepts on the grid.
"Looking at the prototypes and at the CO2 reduction, which is what we're talking about effectively, this is engine efficiency. It's about supercharging, or not, different fuels, especially if we have a bio-ethanol or bio-based fuel content or a blended side that immediately reduces the CO2."
Honda's Clarke agrees with Walliser about the appeal of the ALMS' very open engine rules.
"In the ALMS, you can pick your engine formula whether it's normally-aspirated, or turbocharged, or supercharged, or whether it's an in-line four or V6, or V10 or V12," Clarke said. "To be also able to pick your fuel just adds to that appeal."
Porsche's engineers also like the ACO/ALMS air restrictor rules.
"I think the engine rules in the ALMS with the restrictors always give you a clear indication of the amount of air you have in the engine," Walliser said. "With the amount of air known, it's clear what fuel you can burn and the output is defined. A restrictor drives the engineers to improve the efficiency."
