F1 2026 power unit saga takes fresh twist - report

The contention over F1's new power unit regulations has taken another dramatic turn, with the FIA's original proposal to address the compression ratio issue now reportedly superseded by a new compromise.

According to Motorsport Magazin, the plan agreed at the F1 Commission during last week's Bahrain pre-season testing already looks set to be discarded, with a new plan expected.

The initial proposal would likely have amended regulations from 1st August 2026 after a vote between the five power unit manufacturers — Mercedes, Ferrari, Red Bull, Honda and Audi — F1 and the FIA.

With a super-majority of six votes needed to ratify the change, Mercedes would have been powerless to prevent it, unless F1 or the FIA sided with the eight-time constructors' champion.

It would have seen compression ratio measurements taken under both cold (ambient temperature) and hot (130 degrees Celsius) conditions, as opposed to the current wording of the rulebook, which specifies only ambient.

While Mercedes team principal Toto Wolff had expressed surprising support for the proposal, it was the other manufacturers who objected to the plan.

Rival power unit providers took exception to measurements being required under both temperature conditions, and consequently, a fresh compromise has now been brokered.

The new agreement brings forward the deadline from 1st August to 1st June, whilst implementing a two-stage approach — again, unless F1 or the FIA sides with Mercedes.

From 1st June, compression ratio measurements will be taken under both cold and hot conditions for the remainder of the 2026 season. However, from 2027 onwards, measurements will only be conducted in hot conditions.

The revised proposal offers Mercedes' competitors significant advantages beyond the accelerated timeline.

By mandating hot-condition-only measurements from 2027, Mercedes — and its customer teams — would derive no benefit from its innovation from that point onwards, as it would need to make changes to its power unit under that eventuality.

Under the dual-measurement system, Mercedes would have retained some advantage, albeit reduced compared to its current position.