Why Mercedes and Red Bull engines face heat ahead of 2026 F1 season

The article discusses a controversy emerging ahead of the 2026 Formula 1 season involving engine compression ratios, specifically focusing on Mercedes and Red Bull. The FIA has set new regulations for 2026 that reduce the maximum permissible engine compression ratio from 18:1 to 16:1, measured at ambient temperature, to encourage more manufacturers to join the sport. However, Mercedes and Red Bull have reportedly found ways to increase their engines' effective compression ratios on track by exploiting the fact that engine components expand with heat, which increases compression ratio beyond the regulated limit when measured under race conditions. This loophole potentially allows their engines to operate closer to the previous 18:1 ratio, giving them a significant power advantage of 10-15 horsepower and thus a competitive edge over other teams. The issue has caused concern among rival teams, as the advantage could effectively predetermine the competitive order before the season even starts, especially since the FIA controls fuel flow rates that further influence engine performance. The FIA has