Lawson at risk of Mexico qualifying DSQ

Liam Lawson’s top-10 start in Formula 1’s Mexico race is in jeopardy after he and his Racing Bulls team were summoned to the stewards for a technical infringement.

Lawson qualified eighth-fastest in Mexico City though would start ninth at best due to a one-place grid penalty picked up for his needless clash with Max Verstappen in Friday practice - which he has apologised to Verstappen for.

However, Lawson may not start near the points at all after being reported for a breach of F1’s complex MGU-K power deployment rules just after finishing his final lap in Q2.

Technical breaches are usually a black-and-white matter that result in disqualification.

The rare alleged breach is that “the driver maximum power demand and the electrical DC power of the [MGU-K] were reduced at greater rates than what is permitted”, according to FIA F1 technical delegate Jo Bauer.

Essentially, when the Q2 lap ended, Lawson’s car lost all electric power deployment too suddenly.

The battery-powered MGU-K adds up to 350kW on top of the engine but when that boost has to end the rules don’t let it switch off in one go.

It has to fade out gradually, by no more than 50kW or 100kW each second depending on the track. A full cut takes several seconds.

The “driver maximum power demand” is the total power the car makes available to the driver at full throttle while the “electrical DC power of the MGU-K” is what is actually coming from the battery motor.

Both have to come down gradually but the delegate’s report says they dropped faster than allowed.

This could relate to a trick that has been deployed by Mercedes and Racing Bulls’ engine supplier Red Bull Ford Powertrains at points this year.

They found a way to bypass the staged rampdown by utilising a failsafe mode that allows for the MGU-K to be cut to 0kW instantly.

It is designed to be used in emergency situations but was never regulated as such, and the price paid is that the team is then ‘locked out’ of using the MGU-K for a full minute thereafter.

In order to trigger this mechanism, drivers were lifting sharply just before the finish line.

This was considered potentially unsafe, though, as it led to cars slowing and sometimes stopping completely on-track if the loss of the MGU-K coincided with turbo boost pressure dropping too low and engine power basically being lost completely.

A subsequent workaround was discovered. The regular 50kW drop every one second can be avoided if the driver power demand is negative and the ICE power is negative and the ERS-K power needs to be reduced further to achieve the driver demand.

The former can be achieved if drivers could lift off the throttle just before the end of the lap, which can be a worthwhile trade-off where there is a relatively short run from the final corner to the timing line.

This may explain why Lawson’s team-mate Arvid Lindblad was lifting just before the end of his laps in qualifying - but Lawson himself stayed flat out on the lap in question, and so the driver power demand would not have been negative.

If this was followed by the MGU-K power being cut instantly, it may explain the breach flagged by the FIA.