Two-stroke engines or motors running on hydrogen could be back in MotoGP by the middle of this decade if targets to make motorsport more carbon neutral are to be achieved.

Stinkwheels, as the Americans lovingly referred to them, were canned in MotoGP at the end of the 2001 season as the emissions were far too high and four-strokes were brought in - some say at the behest of Honda - to made reductions.

But with new direct injection, pressure charging and other technologies, two-strokes are now more efficient than four-strokes. And hydrogen engines only emit water at the end of a combustion cycle but that tech is still very expensive.

F1 chief technical boff Pat Symonds is keen on using a two-stroke formula in its new specification of engine unit in 2025 and MotoGP might follow the same ideas in order to also share development costs.

“I’m very keen on it being a two-stroke. Much more efficient, great sound from the exhaust and a lot of the problems with the old two-strokes are just not relevant any more,” he said.

“Direct injection, pressure charging, and new ignition systems have all allowed new forms of two-stroke engines to be very efficient and very emission-friendly. I think there’s a good future for them.”