F1 moves to close loophole in new engine rules

Formula 1 bosses are moving towards a rule change that would close a loophole rivals believe Mercedes have exploited in the sport's new engine rules.

Audi, Honda and Ferrari fear Mercedes have found a way to use thermal expansion and materials technology to exceed the mandated compression ratio.

The current rules state the maximum compression ratio of 16:1 is to be measured at ambient conditions but Mercedes are claimed to have found a way to exceed this when the engine is running at temperature.

It has now been proposed that the rule will be changed from 1 August to ensure the compression ratio is measured at a "representative operating temperature of 130C" as well as at ambient temperature.

This will now go to a vote of the power-unit manufacturers, along with the FIA and commercial rights holder F1, where it is expected to pass.

That would effectively give Mercedes the first 13 races of a 24-race season to exploit whatever advantage they may have achieved from their technology, if their engine is indeed exceeding the compression ratio at any point.

Mercedes team principal Toto Wolff insists their engine is legal and that its design has been approved by the FIA.

The compression ratio is a measurement of the cylinder displacement between the two extremes of the piston stroke. Rivals believe increasing this beyond 16:1 could give a gain of as much of 0.3 seconds per lap.

Williams team principal James Vowles, whose team use Mercedes engines, dismissed the debate as "just noise that will probably go away, probably in the next 48 hours".

Red Bull's position on the compression ratio argument has not been clear until now, following their entry as a power-unit manufacturer this season.

Red Bull team principal Laurent Mekies said on Wednesday: "We don't think it's noise. We think we must have the clarity on what we can and cannot do."

The new engine proposal came on the same day as the F1 Commission discussed a variety of issues that have arisen from the first running of the cars under the new rules introduced this year.

These included the increased difficulty of the start process and the way energy deployment and recovery are controlled by the rules.

The new power units introduced this year have a near 50-50 split between internal combustion engine and electrical parts of the engine and are energy starved as a result of the way the rules have been defined.

There is increasing concern within F1 about the degree of energy management the drivers are being forced to take on and the discussions centre on ways to make this less of a feature.

A statement from the FIA said: "Further evaluation and technical checks on energy-management matters will be carried out over the following three days at the second pre-season test in Bahrain.

"It was agreed that no immediate major regulatory changes were required, given that initial evidence and feedback remains immature and that premature change carried the risk of increased instability ahead of the first race. Further reviews will be carried out once more data becomes available."

The concern over the start process is centred on the increased amount of time it takes to get the turbos in the engines spooled up to the right speed for the optimum launch.

This is taking in the region of 10 seconds following the removal of the MGU-H, the part of the hybrid system that recovered energy from the turbo and could be used to eliminate lag. A new start process is expected to be introduced giving drivers extra time before the start-light process begins.