During pre-season testing in Bahrain, Mercedes team principal Toto Wolff expressed concern that his team would face challenges if the FIA adjusts compression ratio checks for the 2026 Formula 1 season. Rivals are pushing for changes to measurement procedures, arguing that Mercedes engines exceed the 16:1 limit on track despite complying in static tests. Wolff emphasized that all Mercedes engines are fully legal and rejected any plans for legal action.
The controversy over Mercedes' 2026 power unit dominated discussions at the Bahrain International Circuit during the opening day of Formula 1 pre-season testing on February 11, 2026. Mercedes engines meet the 16:1 compression ratio during static tests at ambient temperature, but achieve a higher ratio while running on track, prompting complaints from rivals including Audi, Ferrari, and Honda. These manufacturers sent a joint letter to the FIA seeking clarification, while Red Bull's stance appears more reserved.
Toto Wolff, Mercedes team principal, addressed the media, stating, "I'm a little bit more confused in the recent weeks about how it came to the point now that it suddenly became a topic, because until last Friday, I was given the impression that things wouldn't change." He learned of potential changes from an Italian website article and noted increased lobbying, including "secret meetings" and letters to the FIA. Wolff warned, "If they decided to share an opinion and an agenda, then you're screwed," referring to the need for a supermajority in the Power Unit Advisory Committee—four of five engine manufacturers, plus the FIA and Formula One Management.
Williams team principal James Vowles defended Mercedes, insisting the power unit is "completely compliant with the regulations." He argued against intervention, saying, "We, as a sport, have to take care that this is not a BOP series. This is a meritocracy where the best engineering outcome effectively gets rewarded." Vowles highlighted the complexity of altering procedures, noting it could disqualify eight Mercedes-powered cars, including Williams, from the Australian Grand Prix on March 8.
Wolff dismissed rumors of legal action, affirming respect for the sport's governance: "If the governance of the sport decides to change the rules, be it against our position or for our position, we just have to get along with it." He downplayed performance impacts, calling it "just a few horsepower," and stressed unknown consequences for engine development and the ADUO balancing system.
Meanwhile, Wolff praised Red Bull's new in-house engine as the current benchmark, citing its superior energy deployment over consecutive laps. George Russell added that any rule change would require adherence, but lead times make modifications challenging, with consequences for the Melbourne opener remaining "unclear."