Why Ferrari believes F1 engine rules tweak won't stop Mercedes
With the compression ratio loophole to be closed, Mercedes is set to lose performance – but Fred Vasseur doesn’t reckon it will be a game changer
Motorsport photo From 1 June, new FIA tests for Formula 1 engines mean Mercedes ’ compression ratio loophole will be closed – but it may not be sufficient for Ferrari to catch up. As the world championship switched to new power units for 2026, the internal combustion engine’s compression ratio was reduced from 18:1 to 16:1. However, the ratio is checked at ambient temperature, and Mercedes found a way to expand it when the engine is running.
The Anglo-German team played the trick down, with team principal Toto Wolff arguing it was worth 2-3hp, while Red Bull’s Max Verstappen retorted “you definitely have to add a zero to that, and maybe even more”. As Mercedes’ main – and arguably only – challenger in the first two grands prix of the season, Ferrari might be closer to Wolff’s stance. “I'm not convinced that the new compression ratio rule will be a huge game changer,” team boss Fred Vasseur said.
“It's more that you will have the ADUO at one stage – the introduction of the ADUO will be an opportunity for us to close the gap. ” Frederic Vasseur, Ferrari Frederic Vasseur, Ferrari The ‘Additional Development and Upgrade Opportunities’ mechanism means that power units will be evaluated after the sixth, 12th and 18th grands prix of the season. Each time, manufacturers that are between 2% and 4% down on the best engine’s power will be allowed an additional upgrade, while those who are more than 4% down will get two.
In the 2026 season, this was going to happen after the Miami round in May, Spa-Francorchamps in July, and Singapore in October. However, the cancellation of April’s Middle Eastern rounds means the evaluation will now take place after June’s Monaco race, August’s Zandvoort round and the Mexico City GP on 1 November. “But once again, it's not just about pure ICE performance,” Vasseur insisted.