Essentially a twin-turbocharged, high-performance version of the B58 already available in the Supra 3.0, the S58 straight-six mill is already available in the BMW X3 M and X4 M, where it produced 480 horsepower in the regular versions and 510 horsepower and 600 Nm (443 lb-ft) of torque in the Competition models.
Such a huge power upgrade would translate into massively better performance numbers, which were obviously expected from a potential GRMN edition of the Supra anyway.
Apparently, BMW M’s head honchos were not as happy to give away the twin-turbo mill to the Japanese, but Tetsuya Tada, also known as Mr 86, allegedly sweet-talked the Germans in the end.
The Toyota Supra GRMN would be launched toward the end of the current generation’s production cycle as a limited edition model with the starting price expected to get scarily close to the $100,000 mark.
The same Japanese source also mentions that there are currently no plans for a replacement model of the Supra GR, which should end its production sometime in 2025.
Almost all of that sounds swell, but keep in mind that the current, fifth generation of the Supra is more of a BMW Z4 in a coupe body, with most of the technical bits under the hood being sourced from BMW.
The Bavarians have no plans to offer the S58 engine on the Z4, but they may reconsider it if this Supra GRMN rumors turns out to be true. Heck, they already have it in a couple of crossovers, so why not on a roadster as well?