Engine and transmission details about Supra and BMW Z4 discovered

It's official: the new fifth-generation Toyota Supra and third-generation BMW Z4 will be powered by both four- and six-cylinder turbocharged petrol engines.

Road & Track has uncovered documentation from transmission maker ZF detailing the drivetrain choices of both the new Supra and its twin-under-the-skin BMW Z4.

According to these documents, the base Supra will be powered by a turbocharged 195kW 2.0-litre four-cylinder engine (B48B20), while the higher-spec variant features a 250kW 3.0-litre straight-six (B58B30). Both petrol motors come from BMW, and are paired with a ZF eight-speed automatic.

In addition to these two drivetrain combinations, the Z4 will also be available with a 280kW version of the six-cylinder mill. This engine seems likely be used by the Z4 M40i, which was recently teased by the Bavarian automaker.

Testsuya Tada, chief engineer for the new Supra, confirmed the availability of both four- and six-cylinder engines to the magazine. He also noted the four-cylinder will not only be lighter, but have "much better weight distribution", and a sharper turn-in.

Tada cheekily points out anyone hoping to swap Toyota's old 2JZ straight-six engine into their new Supra should go for the four-cylinder model, as it will be cheaper.