RacingThe FIA has shut down the MGU-K shutdown trick before Miami, banning a qualifying exploit used by Mercedes- and Red Bull-powered teams to blast to the line with about 50 to 100 kW of extra battery power for a few hundredths of a second, according to The Race. The directive takes effect from the Miami Grand Prix in early May.
The Race reports teams had been switching the MGU-K off just before the timing line to avoid the mandatory end-of-lap power ramp down. That rule normally forces a reduction of 50 kW per second as energy use peaks, so drivers would otherwise arrive at the line with less electrical boost. By mimicking an emergency shutdown, cars could keep full deployment to the stripe, then live with the consequences once the lap was over.
According to The Race, the workaround leaned on a 60-second continuous offset lockout that follows an MGU-K shutdown. Trigger it just before the line, and the 60-second penalty bites on the slow-down lap when the 350 kW MGU-K is not needed. The gain was small on the clock, but enough to matter in tight qualifying splits.
Rivals first noticed the approach in Australia, The Race says, but it flared at Suzuka. In practice, Mercedes' Kimi Antonelli and Red Bull's Max Verstappen were left limping with no MGU-K power, and Williams' Alex Albon even stopped on track due to complications linked to the tactic, according to the same report. The FIA intervened because the method clashed with the intent of the rules and raised safety concerns, despite the advantage amounting to only a few hundredths on most tracks.
Ferrari initiated talks with the FIA after spotting the trend, The Race reports, accepting the trick was legal but warning it carried safety risk. In the wake of manufacturer discussions at Suzuka, the governing body put the new stance in writing. The FIA, Formula 1's governing body, wrote in a communication to teams reported by The Race: "While the option to disable the MGU-K remains available to teams, using this function for purposes other than legitimate ones will not be tolerated."
The Race says the FIA will now police end-of-qualifying-lap data to check any MGU-K shutdowns are genuine emergencies. The ban, framed around safety and the purpose of the hybrid deployment rules, will apply from Miami and removes the late-lap electric blast that some power units had been exploiting.