This weekend it's the start of the Intercontinental Le Mans Cup in sports car racing with the 12 hour endurance event at Sebring in Florida.
And this year there are new regulations for the powerful diesel cars to try to narrow the gap with their petrol counterparts.
Peugeot is racing their 908 car in the LMP1 category, but with significant modifications this season. The engine is a 3.7L, V8 turbo-charged diesel delivering 550hp, roughly 150hp down on last year's 908 Hdi FAP.
And the new changes are clearly apparently to British Peugeot works driver Anthony Davidson, as he explained to Le Mans Live at Sebring.
"Performance is obviously not as good. We are about 5 seconds slower this year with the new regulations.
"(It's) difficult to forget last year's feeling in the car. Obviously you had more power, more grip so you forget that as much as can.
"You find yourself overdriving in the beginning and you are expecting too much from the car so we are having to restrain ourselves and relearn the car around this circuit. But I think come the race we will be more confident."
Watch the Le Mans Live interview here:
In the last couple of hours, Davidson took P1 in the overnight testing ... ahead of arch rivals Audi. Qualy today should be interesting.
The 12-hour race can be watched live on www.americanlemans.com.