FIA introduces rule change in regulations concerning Mercedes' power unit 'trick'

Ahead of the upcoming Formula 1 season, Mercedes' reported compression ratio 'trick' was a much debated topic in the paddock.

From 1 June, power units will not only be measured at ambient temperature, but also when it is at 130 degrees Celsius, when Mercedes' engine's compression ratio is said to increases from 16:1 to 18:1.

The change was approved unanimously by the World Motor Sport Council.

In Issue 16 of the Formula 1 regulations, section C5.4.3, the previous rules are crossed out.

It now reads: "No cylinder, as referred to by C5.1.3, of the Engine may have a geometric compression ratio higher than 16.0, measured in the following conditions:

From 2027 onwards, it will be only measured in the operating conditions.