It’s no longer a secret that Yamaha, MotoGP’s sole manufacturer with an inline four configured engine, is already working on a new V4 powerplant for the future in an attempt to close down the top speed and corner exit advantage currently enjoyed by its rivals.
But under the new rules coming in 2027, making that switch might well become essentially mandatory.
Yamaha became the last V4 outlier in 2023 following the departure of Suzuki from the grid, but has nonetheless stuck with the different configuration thanks to its smoother power delivery and better corner speed, attributes that have traditionally been hallmarks of the M1 machine.
Under Yamaha’s concession status, it could actually switch to the V4 during the 2025 season.
But its proposed debut has recently been pushed back by new team boss Paolo Pavesio - no great surprise given the considerable amount of work that’s required to build not just a new engine but a whole new bike to mount it in thanks to the V4 configuration’s completely different shape.
Mounting two blocks of two cylinders each together in a V shape, rather than having all four alongside each other in a line, means that the new M1 will be narrower - and in that narrow shape lies a clue as to why V4s might essentially become mandatory not just for Yamaha but for everyone when new rules are introduced in 2027.
Yet surprisingly, it’s not the new engine rules that will cut the bikes from 1000cc to 850cc that’s going to cause this, but rather the updated aerodynamics regulations that will come with them.
In an attempt to reduce complexity and clear up the phenomenon of ‘dirty air’ (turbulent airflow generated by the wings) in order to reduce cost and increase overtaking, the width of aerodynamic devices allowed by manufacturers will essentially be cut in half.
These new rules will be policed in the same rather crude but effective way as they currently are, according to The Race’s sources in the paddock: by using a large metal box shape that bikes must simply fit inside.
And therein lies the benefit of using a V4 engine, considering that it’s one size of box that fits all bikes within the set dimensions regulated by the rules.
Simply put, the narrower the core component of your bike is, the more room within that box you have for aerodynamic devices. A thinner engine configuration means you can use bigger wings, retaining some of the downforce advantage currently enjoyed that the new rules are trying to reduce.
Though it’s now admitting it has a V4 on the way, Yamaha has not yet formally committed to racing it - and some of its riders aren’t even sure it needs it. KTM convert Jack Miller recently suggested the V4 was “a fad, I don't believe it's set in stone that you need a V4” and argued that the “inline-four we've got at the moment is pretty strong”.
But regardless of that, Yamaha’s hand might well be forced into ditching the inline four that’s been the centrepiece of its MotoGP programme since the very beginning of the four stroke era in 2002 - and its production racing programme for long before that.
