Mercedes-Benz has become the second engine maker in F1 to break the elusive 20 000r/min barrier.
Williams' current supplier, Cosworth, was the first to reach the milestone in qualifying trim, but at Magny Cours Mercedes' Norbert Haug reportedly took great delight in overseeing the achievement in the back of a silver McLaren racer.
"We've cracked 20 000," he was quoted as saying by Eurosport AutoMagazin.
Earlier this season, the results of an acoustic study showed that the third and fourth highest-revving V8 power plants in pitlane belonged to BMW and Ferrari.