Mercedes clever qualifying loophole explained in major qualifying boost

Mercedes have developed an ingenious method of squeezing every last watt of electrical energy from the MGU-K in qualifying, exploiting a legal interpretation of the regulations that allows the power unit component to cut its output far more sharply than the rules originally intended.

Under the current regulations, when the MGU-K is switched off, teams must follow a progressive power reduction ramp for safety reasons, with a maximum reduction of no more than 50 kW per second. 

Earlier this season, both Mercedes and Red Bull had been using an emergency shutdown procedure to bypass this ramp entirely, deactivating the MGU-K outright. 

The FIA moved to ban the practice in qualifying after determining it posed a potential safety risk, given that the MGU-K could remain inactive for approximately a minute.

Mercedes, however, have not simply accepted that restriction. The Brackley-based outfit have since identified a separate, entirely legal interpretation of the regulations that achieves a near-identical result.

How Mercedes' MGU-K trick works

The regulations do permit the standard power reduction ramp to be bypassed in specific circumstances, one of which occurs when the driver lifts off the throttle completely. 

At that point, with the internal combustion engine no longer producing power, the MGU-K is also permitted to reduce its rotational speed and electrical output more abruptly.

Mercedes have programmed their control unit to pinpoint the car's exact position on the circuit at the precise moment the driver lifts off. 

By lifting just a few metres before the finish line at the end of a qualifying lap, the MGU-K can instantaneously cut its power output rather than beginning the gradual reduction ramp prematurely, all while remaining within the letter of the regulations.

The system demands an extraordinary degree of precision. The driver must lift at exactly the correct point, and the control software must simultaneously calculate when the battery is on the verge of depletion and confirm the car's precise location on the circuit.

Only then can the MGU-K continue deploying maximum electrical power right to the very last possible moment of the lap.

Whether the FIA will take a similarly dim view of this new approach remains to be seen, but for now, George Russell and Kimi Antonelli have a notably powerful tool at their disposal when the lights go out for qualifying.