No longer a rumour, the Supra GRMN was spotted last week for the first time. Complementing the spy shots is a new video with the amped-up coupe being tested at and around the Nürburgring. We can't say with certainty that it had a manual gearbox, but the professional spy photographer claims the prototype did indeed have a clutch pedal.

When the car came out for the 2020 model year in the United States, it had a BMW-sourced 3.0-litre engine producing just 335 bhp before it was bumped to 382 bhp for 2022MY. A year later, a six-speed manual was added. The German automaker offers a stick shift with a significantly stronger engine as the base M4 has 473 bhp and three pedals. However, it's unclear whether the Zupra will keep the B58 or it's going to receive the M4's S58.

Toyota Supra GRMN spy photos

Perhaps the Supra GRMN won't be allowed to step on the M4’s toes, so one can speculate it’ll have less punch. Lest we forget, the same S58 engine is detuned to 453 bhp in the M2, which is rumoured to get a power bump to 473 bhp at some point in 2024. Even if BMW doesn't want the range-topping Supra to clash with the M2 either, Toyota would still have a lot of wiggle room considering the Supra 3.0 has less than 400 bhp.

But what if the sound you're hearing doesn't come from the S58 but rather from the B58? In its highest state of tune, this non-M engine produces 382 bhp in the current Supra and the M240i. It’s unclear whether there’s room for more. To earn the GRMN badge, Toyota surely wants to add a significant amount of power over the GR, which may not be achievable with the B58. A detuned S58 seems more like an educated guess.

BMW has been making some extra money lately by allowing other brands to use its engines. The Ineos Grenadier off-roader also has the B58 together with the diesel B57, another inline-six. In addition, the new Range Rover and Range Rover Sport have a brawny V8 of Munich origins.