The Balance of Performance probably won’t decide who wins the Le Mans 24 Hours this year. But it could determine who doesn’t. In the two years since the mass influx of manufacturers into the World Endurance Championship’s Hypercar class there have been haves and have nots in terms of the BoP at its blue riband event in France in the middle of June.

It wouldn’t be a stretch to say that there were only a handful of manufacturers who could win the big race in 2023 and ’24. The BoP, the means by which the playing field is levelled in Hypercar, didn’t give everyone a fighting chance. It was pretty much Ferrari vs Toyota each time, with Cadillac not far behind in ’23 and, along with Porsche, again in ’24. There’s room for improvement, and the WEC rule makers, the FIA and the Automobile Club de l’Ouest, concede that. The system by which the BoP is calculated remains a work in progress, they say. There have been further tweaks for 2025 as they refine a process driven by race data brought in last year. That included the introduction of the ‘power gain’ element at Le Mans, an adjustment of the maximum performance from the powertrain allowed above 155mph.

A tool that aims to balance the straight-line speeds of the cars is more relevant on the Circuit de la Sarthe with its four flat-out blasts, on the Mulsanne Straight and then on the run to Indianapolis, than anywhere else on the WEC calendar. A season’s worth of experience with ‘power gain’ could be crucial as the FIA and the ACO strive to bring the field together for the most prestigious race of the year.

The problem is that an eight-and-a-half-mile circuit, which is more than 50% public road, is the outlier on the schedule. It’s why the WEC organisation insists that the French race has its own BoP, without explaining exactly what that means.

The BoP for the regular WEC introduced for last year is distinct from the one in force in 2023 when simulation was the primary tool used in its calculation. That was when the rule makers unilaterally changed the BoP at short notice ahead of the first track action at Le Mans – although the guidelines laid down to the manufacturers said they couldn’t. This wiped out Toyota’s large advantage in the opening three races and handed a narrower one to Ferrari.

The FIA and ACO admit that simulation is still a key tool in the formulation of the Le Mans BoP courtesy of the unique characteristics of the circuit. Given that the BoP can’t change – or rather shouldn’t under the latest guidelines – between the pre-event Test Day, the Sunday ahead of race week, and the race itself, they have one opportunity to get it right.

The pressure is on with an increasing number of factories on the grid for them to get the BoP bang on the money. Because that’s why manufacturers are spending large amounts to chase victory. Success comes with a prestige that significantly outweighs that attached to winning any of the end-of-season silverware on offer in the WEC. For all the continuing growth of the Hypercar division, the have nots might decide they don’t want to continue putting their hands in their pockets.

No one wants to go to Le Mans without a chance of a result.