It's been six years since we learned of the BMW-Toyota joint sports car project, and next month we'll finally see what Toyota has created in the form of the all-new Supra. BMW previously unveiled its version, the new Z4, last summer. While both share a platform and an engine, the two vehicles have very different characters and even body styles. However, Toyota realized early on that if it wanted to do a reborn Supra, it would need an inline-six engine. Every previous Supra had one, and the Japanese have great respect for tradition.

Problem was, Toyota didn't build an inline-six and it made no financial sense to spend boatloads of money to design and engineer one for a single model. What to do? Call the current inline-six experts, BMW.

Automotive News Europe spoke with the all-new, fifth-generation Supra's chief engineer, Tetsuya Tada, ahead of the car's debut in a few weeks at Detroit, and was told the inline-six engine was a non-negotiable item. "The straight six is the only engine with perfect balance and low vibration. We can realize smooth driving with exciting sound," Tada said. With more than 300 hp on tap, this new 3.0-liter six-cylinder turbo sure sounds like it'll deliver the goods, but Toyota has not yet released official specs.

Toyota further realized this engine would be best suited with the same eight-speed automatic transmission also shared with the Z4, but Tada and his team made plenty of adjustments of their own. Engine, gearbox, and chassis have all been uniquely tuned for the Supra.

Not surprisingly, CEO Akio Toyoda, a long-time racing fan and highly experienced driver, has personally been testing prototypes for the past three years, offering plenty of input. "It was only recently that he started smiling a little, and said 'it has become better'", Tada added. And speaking of racing, we've already seen the GR Supra Super GT Concept, which clearly indicates Toyota's Gazoo Racing division has some future plans.

Toyota's current sports car, the 86, also lacks a Toyota-developed engine, utilizing one from Subaru, which builds the BRZ twin. Tada hinted but refused to divulge details that Toyota is quietly developing sporty engines of its own. We'll bring you plenty of more details next month from Detroit where we'll be on hand for the new Supra's big reveal.