BMW's two Schnitzer-run M3s will race at the Le Mans 24 Hours with fractionally smaller inlet restrictors after race organizer the Automobile Club de l'Ouest (ACO) moved to peg back the car's performance.
The change – believed to be four tenths of a millimeter – will reduce the engine's peak power by 10hp.
"We have a smaller restrictor now," said Dirk Muller. "It is how it is – I can't change it. We'll have to make the best with what we have. That's racing."
The German former World Touring Car frontrunner is competing at Le Mans for the first time since 2000.
"This is a new car and it's performing very well," he said. "It'll take me a couple of laps to get back into the rhythm, that's for sure, but I still know my way around."