Yamaha V4 vs Inline: Lap time difference for Rins, Miller at Misano MotoGP Test

Alex Rins and Jack Miller provided the clearest comparison yet between the performance of Yamaha’s new V4 prototype and the current Inline M1 during Monday’s Misano MotoGP test.

While team-mate Fabio Quartararo spent a full day on the V4, Rins completed 46 laps on the standard M1 in the morning before switching to the prototype for 34 laps in the afternoon.

The Spaniard recorded a best lap of 1m 31.571s on his Inline race bike, then 1m 32.101s on the V4, a difference of 0.531s (see table below).

Comparing the time gap to the top - to take improving grip conditions in the afternoon into account - Rins was 0.857s behind Alex Marquez in the morning and 1.727s from Pedro Acosta in the afternoon, a deficit of 0.870s.

“I'm quite happy with how the bike works,” Rins, who won the 2023 COTA Grand Prix on a Honda V4, told MotoGP.com.

“For sure. It's a really new project that Yamaha invests a lot of time in, and to have two bikes for the Yamaha riders to test here was really, really great. I'm so grateful for that.

“I tried to adapt myself to the bike because it was not easy. We only rode in the afternoon. Overall it was quite positive. I'm happy because I feel like braking was a little bit better compared to the Inline4.

“It's a thing that we were suffering a lot with brakes and with the V4 it came natural. For sure, there is a lot of room to improve. It’s only the second time that we jump on track with this bike and as I said, it's a really, really new project.

“For sure, the next time that we jump on the bike, it will be different. Different parts in the bike.

“I'm so happy. Still, as I said, there is a lot of room to improve in power, in handling, in many, many aspects. But they are working hard and we are in a good way.”

Jack Miller’s lap time comparison

While Rins switched from Inline to V4 on Monday, Pramac’s Jack Miller went in the opposite direction.

The Australian started on the V4 before handing it over to the Monster Yamaha rider for Session 2.

Miller set a 1m 32.635s (+1.921s) on the V4 in the morning, improving to a 1m 31.660s (+1.286s) on the Inline. That’s a lap-time difference of 0.975s and ‘gap-time’ difference of 0.635s, similar to Rins’ numbers.

“The engine character is nice. Having that inertia, and being able to work with that inertia,” said Miller.

“The electronics need a lot of work.  Obviously, after 20-something years of working with an inline, none of the mapping or throttle control or any of the electronic side really is compatible.

“So it's a whole new process of building and improving every single time we exit the garage. And that was what today was all about. Every single time we exited the garage, it got better. It got more usable, more rideable. Connection was clearing up in small micro increments.

“You need at least a week for all that. So we're on the good way. The traction area is there. The nice thing about this V4 that, even though we changed basically everything on the motorcycle, that Yamaha DNA of having a solid chassis underneath you still seems to be there.

“This will not be the bike that we have in Valencia in terms of chassis and so on and so forth. So as a first version, we're in the ballpark.

“For me, to be 1.9s off the pace in the morning, and Fabio even closer. It's not bad. It's a good base.”

V4 Lap Time Comparison:

V4 'Gap-Time' Comparison (to Fastest Rider):

Meanwhile, Quartararo was less upbeat about the new bike, saying he failed to feel any real benefit from the V4 at Misano.

The Frenchman set the fastest V4 time with a 1m 31.598s in the afternoon, good enough for 18th on the combined timesheets (+1.224s from Acosta).

Monday was the second time that Quartararo, Miller and Rins had tried the V4, after making their debut at a private post-race test in Barcelona.

Test rider Augusto Fernandez, who finished 14th on the V4 in Sunday’s San Marino GP, will be back for further wild-card appearances at Sepang and Valencia.