Marc Gene thinks F1 could theoretically switch to diesel power in the future.
The Spaniard, who is an official test driver for Ferrari, recently got his first taste at the wheel of the Peugeot 908 prototype, with which he will race at Le Mans later this year.
Gene told the newspaper Diario As, "After not really knowing what to expect, I can say that this is a proper racing car that you can compare in some respects with a F1 car, including the power output."
Audi won Le Mans last year with its diesel-powered R10, amid claims that the technology boasts better fuel consumption with similar power and torque.
F1 is toying with the concept of using so-called 'biofuels' in the future.
"After driving the Peugeot I believe that diesel is feasible for formula one," Gene said.