Bernie Collins Questions Effectiveness of New FIA Compression Test as Temperature Gap Emerges

Former F1 engineer Bernie Collins warns that the FIA's new 130°C compression test may fail to capture actual 400°C engine conditions in 2026.

By: AXL Media

Published: Apr 10, 2026, 3:58 PM EDT

Source: Information for this report was sourced from PlanetF1

The 2026 Compression Ratio Controversy

As Formula 1 enters the summer phase of the 2026 season, the "compression ratio saga" has emerged as the most significant technical debate in the paddock. The controversy centers on allegations that Mercedes found a way to satisfy existing ambient-temperature tests (16:1 ratio) while significantly increasing compression once the engine reaches racing temperatures. Higher compression results in a more powerful combustion "bang," potentially providing a performance benefit of several tenths of a second per lap—a margin that aligns with Mercedes' dominant start to the season.

Bridging the 130°C to 400°C Divide

To address these concerns, the FIA has mandated a new "hot" compression ratio test effective June 1, 2026. This test requires engines to meet regulations at a temperature of 130°C. However, speaking on Sky’s The F1 Show podcast, Bernie Collins highlighted a potential flaw in this regulatory fix. "These engines run very, very hot," Collins explained. "We’re bringing in a test at 130 degrees [sic], but I’d estimate the engines are something like 350, 400 degrees. So it’s a big, big difference." The implication is that if a team has engineered materials to expand or shift at the highest end of the thermal spectrum, a test at 130°C may still fail to capture the engine's true racing configuration.

Historical Context of Midway Rule Changes

Collins likened the current situation to previous technical battles, such as the mid-season adjustments to rear-wing flexibility tests. In those instances, the FIA increased the load requirements during scrutineering to prevent wings from "flexing" at high speeds—a behavior that was not captured by stationary, low-load tests. The compression ratio challenge follows a similar logic: teams are reading the rulebook to determine what the tests do not say, leading to innovations that bypass the spirit of the law while remaining technically compliant with the letter of the current testing procedure.