Big changes in MotoGP aren’t just about engines anymore. According to Pramac rider Jack Miller, the real game-changer is the rear tire—and it’s the main reason why V4 engines have taken over MotoGP.
Miller believes the evolution of Michelin’s rear tire over the past two to three years has shifted the technical balance strongly in favor of V4-powered bikes.
Rear Tire Becomes the Key Factor
Speaking in a relaxed but honest tone, Miller explained that the current Michelin rear tire has massive potential—but it’s extremely sensitive.
“The rear tire now has huge potential. But to unlock it, the bike has to be fully connected to the asphalt,” Miller said.
This tire isn’t just for acceleration. It plays a critical role in braking, corner speed, and drive out of turns. The problem is its operating window is very narrow. A small setup mistake can completely kill performance.
But when everything clicks, the difference is enormous.
Why MotoGP Performance Swings So Wildly
This sensitivity also explains why MotoGP results can change dramatically from one race weekend to the next.
“One weekend a bike can be amazing, the next it suddenly struggles,” Miller explained.
He pointed to Yamaha, which is still using an inline engine. On tracks with lower grip—or when rivals can’t fully exploit the soft rear tire—Yamaha can actually look more competitive.
Meanwhile, V4 bikes rely heavily on that soft rear tire. Without it, riders struggle especially under braking, as they lose the ability to use the rear end to slow the bike effectively.
Yamaha Switches to V4 for 2026
After decades of success with inline engines—including eight MotoGP riders’ titles, most recently with Fabio Quartararo in 2021—Yamaha has made a major decision.
Starting in MotoGP 2026, Yamaha will switch to a V4 engine, following the path already taken by its main rivals.
Despite being behind other manufacturers who have over a decade of V4 experience, Miller believes Yamaha is fully capable of catching up.
“They’re absolutely all-in on this new project,” he said confidently.
Double Challenge: V4 Development and 2027 Rules
On top of developing the V4, Yamaha must also prepare for the 2027 MotoGP regulations, which will introduce 850cc engines and Pirelli tires.
Miller sees Yamaha’s move as a proactive step to stay competitive in the long term.
“They had to do something. This is Yamaha being proactive,” he said.
Yamaha engineers have reportedly been working flat out for the past 18 months—and that intense development effort is expected to continue for at least two more years.
Is the Inline Era Over?
For now, the last MotoGP victory by an inline-powered bike remains Alex Rins with Suzuki at Valencia 2022. Since then, V4 machines have only strengthened their grip on the championship.
Yamaha’s learning process will begin in earnest when MotoGP 2026 testing kicks off at the Sepang Shakedown from January 29 to 31.
One thing is clear: MotoGP is entering a new era—and the rear tire has become the ultimate performance weapon.
