As teams continue developments for the next era of power unit regulations, they have started to discover the performance quirks that are around the corner.
And one of the weirdest aspects of rules that are aimed at being more sustainable is that drivers are going to get engaged in fuel-burning activities once again to try to charge their batteries.
Fuel burn is the activity of deliberately burning through excess fuel that is not needed for direct engine performance.
It achieved infamy in F1 in 2006 and 2007 when drivers had to engage in several fuel-burn laps in the final section of qualifying to try to reduce car weight, prior to a final lap on fresh tyres to set a time.
However, fuel burn was something that also happened in F1's blown diffuser era in the early 2010s when clever engine maps were used to blow either hot or cold air from exhausts off throttle to help feed the diffuser.
With F1's 2026 rules opening up the door for a greater reliance on battery power – which is set to produce 50% of the entire engine performance – teams are searching for ways to help charge batteries.
And one of the best ways that have emerged is for the engines to continue delivering torque to the crankshaft so that energy can be harvested by the MGU-K, even when it is not needed by the driver.
This can be done either by drivers remaining on full throttle under braking, changing down gears on the straights, or through engine maps.
However, if it is achieved, the characteristics will result in fuel burn returning to F1.
Source: Autosport