Why Toyota Didn't Develop an Inline-Six Engine For The GR Supra And Used a BMW Engine

The Toyota GR Supra is hardly a new topic at this point, The long-awaited, fifth generation of the JDM icon has been around since 2020 and despite mixed reception, it turned out to be a very capable sports car that managed to live up to the name. For JDM fans, their biggest gripe was that the GR Supra was a Toyota in little more than name.

Underneath, it was essentially a BMW Z4 with a different body and a few tweaks done by Toyota. BMW is no stranger to partnerships, especially in the past few years, but why team up with the German carmaker instead of developing an in-house inline-six engine? As it turns out, there are a few reasons, one of which is not widely discussed. 

The lack of a Toyota inline-six 

The most obvious reason we know by now is that Toyota did not have its own inline-six that would comply with the latest emissions regulations while offering ample performance. Toyota, instead, decided to source, not just an engine, but an entire platform to make the GR Supra.

But Toyota didn't simply borrow a platform. The BMW Z4 and Toyota GR Supra were co-developed from the start and it is said that Toyota had extensive input in the B58 engine, the software, and other aspects of the two cars’ development. 

BMW's proficiency with the inline-six engine 

The Toyota Supra needed to have an inline-six and the only logical choice for sourcing a powerplant was BMW. No other carmaker has the same number of great inline-six engines as the Bavarian company. Moreover, while many car manufacturers walked away from the inline-six platform in favor of V-6 engines, BMW never stopped making them.

The result was a very capable sports car with a short wheelbase that responded well to even minor modifications while being able to punch above its weight. So much so that the upcoming Toyota Supra GRMN may not be worth the premium that it would, no doubt, command over the regular GR Supra.  

Toyota is focusing efforts in a few different areas 

Toyota would have had no trouble developing a potent inline-six engine, worthy of the Supra. That said, the company's vast resources are focused in a different direction. On one hand, this includes Toyota's efforts to keep the internal combustion engine alive through synthetic fuels. On the other, Toyota's latest partnership aims to accelerate the adoption of electrified mobility in the city by making fast charging stations more convenient and accessible. 

At the same time, Toyota's new four-cylinder engines will replace most of the current powertrains the company offers. These new mills also include a potent turbo-four, which will be featured in the 2026 Toyota Celica G Sport and the new, mid-engine Toyota GR MR-2. Given the modular nature of the new engines, Toyota would have no problem developing an inline-six based on the new turbo-four engine, but at the same time, the company is also trying to reduce its carbon footprint by offering downsized engines. 

The Supra is not going away just yet, but you might not like what's coming

Toyota sales and marketing director for Australia, Sean Hanley, suggests that the GR Supra will continue to be on sale beyond 2026, which contradicts previous statements that the same year would be the swan song of the GR Supra.

The Toyota Supra will have a sixth generation, but it is likely to adopt Toyota's new four-cylinder turbo engine, along with hybrid tech. While not yet confirmed, this would mean the Supra will slot above the next-gen Celica and MR-2, which will use the same engine without electrification. Making the Supra a hybrid sounds like a sacrilege, but Porsche seems to have done it the right way with their hybrid 911.

About the author

Dimitar Angelov's automotive interests made him an expert in a wide variety of vehicles. Japanese brands like Toyota are closest to his heart, although performance cars in general are his favorite segment, which is why he is constantly on the lookout for the best deals on the market. Dimitar Angelov's car passion and knack for the written word led him to complete a Master of Arts in Media and Communications, and classic car restoration. Dim is happy to get behind the wheel of any car and share his impressions. You can follow Dimitar on X, Linked-in, Instagram, and Facebook.

Image source: 2025 Toyota GR Supra