Mercedes has uncovered a clever legal trick involving MGU-K power deployment that gives its drivers a meaningful advantage during qualifying laps at Silverstone.
During qualifying for both races across the British Grand Prix weekend, both Mercedes drivers were seen lifting completely off the throttle just metres before crossing the finish line.
This behaviour is highly unusual, as drivers typically keep the throttle pinned all the way through the timing line to extract every last hundredth of a second.
Despite appearing counterintuitive, the manoeuvre is deliberate and calculated, exploiting a specific nuance buried deep within the technical regulations.
Kimi Antonelli spoke openly about just how unnatural the technique felt to execute at speed during Q3 at Silverstone.
“In Q3 I also had to lift off, and with these power units it’s always a bit complicated because sometimes you have to drive in a way that doesn’t feel completely natural,” Antonelli said.
“You might lose a little on corner exit, but then you make it back because by delaying the moment you get back on the throttle, you have more energy available further down the straight.”
Antonelli also highlighted how critical simulator preparation was in making the technique feel automatic rather than something drivers had to consciously think about mid-lap.
“At first, you even find yourself wondering why you should lift off at all,” he said, adding that team preparation made it “almost second nature.”
The trick centres on a specific FIA safety regulation that requires teams to follow a progressive power reduction ramp when the MGU-K is switched off, limiting the rate of decrease to a maximum of 50 kilowatts per second.
That rule exists primarily to prevent sudden, dangerous drops in power on fast circuits where a car shedding 350 kilowatts instantly could create extreme speed differentials between competing cars.
Earlier this season, Mercedes and Red Bull had found a separate workaround by activating an emergency procedure that shut off the MGU-K entirely, but the FIA banned that tactic for performance use in qualifying after identifying the safety risks.
Mercedes engineers then identified a regulatory provision that allows the power reduction ramp to be bypassed when a driver lifts completely off the throttle, since the internal combustion engine no longer requires electrical assistance at that moment.
By programming the electronic control unit to keep the MGU-K delivering maximum power based on the car’s position on the circuit, Mercedes ensured the battery energy was spent before the driver lifted off just before the line.
That lift triggers an instantaneous shutdown of MGU-K output rather than the gradual ramp, allowing all stored energy to be deployed more efficiently across the lap without breaching the regulations.
The short run from the final corner to the timing line at Silverstone makes this trick particularly well-suited to the circuit, giving drivers a convenient moment to execute the lift cleanly.
McLaren team principal Andrea Stella admitted the tactic caught his team off guard when they first spotted it during sprint qualifying on Friday.
“When we first noticed it yesterday in sprint qualifying, as Antonelli was doing it, it caught us a little by surprise because it’s not something we’d discussed,” Stella said.
Stella also acknowledged uncertainty about whether McLaren could simply replicate the approach without additional development work on their power unit software.
“I’m not even sure it’s available to us, because it probably requires some additional elements, let’s say, in order to exploit the power unit in that way,” he said.
The McLaren principal confirmed that discussions are ongoing with HPP to ensure the team extracts every possible performance gain from what he described as “an extraordinary piece of engineering.”