Formula One engines once screamed past 20,000 rpm before rules reined them in
Spin an engine twice as fast and, in theory, it makes twice the power. Formula One teams chased that idea until their engines passed 20,000 revolutions per minute in 2004 and 2005, more than three times the speed of a similar-sized road car engine. The costs became absurd, and the rule makers stepped in.
Getting there took decades of clever engineering. Until the mid-1980s, metal valve springs capped engines at around 12,000 rpm, because stiffer springs stole almost as much power as they gained. Renault's pneumatic valve springs of 1986 solved that, and every manufacturer used air springs from the 1990s. Earlier, Tony Rudd at BRM had found that an unusually long connecting rod tamed the vibration caused by high revs, an idea Coventry Climax proved in 1963. Pistons now peak at roughly 9,700 times the force of gravity at the top of each stroke.
Regulators kept tightening the screws. Cylinder counts, which once reached sixteen, were cut step by step to six by 2014, forcing short strokes and wide bores that burn less efficiently. The rev ceiling came down from 2007 onward too. For decades efficiency barely moved beyond the 1967 Cosworth DFV.
The 2014 hybrid era flipped the contest. Today's power units are 1.6-litre turbocharged V6s whose fuel flow is capped, so the only way to gain power is to burn fuel better. Rev limits became pointless and were lifted in 2022. Energy recovery motors harvest power from braking and from exhaust gases spinning the turbocharger. Honda's 2021 engine made over 100 kW more than its 2015 unit on the same fuel flow, and it said the 18:1 compression limit had begun to feel restrictive.
The quest began long before the championship itself. A 1901 meeting at Pau was among the first to call its prizes a Grand Prix, and engine size limits have shaped racing since the 1914 French Grand Prix.
Source: Formula One engines
