Take everything with a pinch of salt, but all the details are rather plausible, although it all depends on how BMW can be convinced to lend its most powerful straight-six engine ever to this project.
As you all know, the fifth generation of the Toyota Supra is a technical twin to the latest BMW Z4 G29, although it features a bespoke Toyota body and coupe design instead of being strictly a roadster like its German brethren.
Both the Z4 and the Supra are built on the same production lines by Magna Steyr in Austria and feature identical powerplants, suspension, infotainment systems; you name it.
In fact, the current Z4 not having an M version at this point was the main proof that a Supra with the BMW M3/M4 engine is not going to happen, but apparently, that will also change in the next couple of years.
According to the most recent rumors, a version of the BMW S58 straight-six from the ‘nosey’ M3 and M4 will find its way in both the Z4 and a special edition of the Toyota Supra.
Essentially a twin-turbocharged, high-performance version of the B58 engine that is already available in the Supra 3.0, the S58 straight-six mill currently only powers the BMW X3 M and X4 M, and the recently unveiled M3 and M4, where it produced 480 PS (473 bhp) in the regular versions and 510 PS (503 hp) and 659 Nm (479 lb-ft) of torque in the Competition models.
Apparently, BMW M’s head honcho was persuaded to insert the twin-turbo mill in both the Z4 G29’s M version and the Supra GRMN by none other than Toyota’s Tetsuya Tada, also known as Mr 86. The only way the business case for either model would be convincing is if they would be treated not like traditional halo models but limited-production versions that can request a lot more money for their exclusivity, not necessarily for their performance.
Neither the current Z4 nor the Supra is a huge seller, so a super expensive, limited-edition version for either model should only make them more desirable for both collectors and pursuers of performance.
While the Z4 M would be unveiled first, the Supra GRMN would be launched toward the end of what may very well be the last generation of the Supra powered by an internal combustion engine.
Think of it as a 500+ horsepower swan song with a starting price that would get close to the $100,000 threshold.