Mazda Built And Killed A V6 Miata

Since the dawn of time, the Miata has been faithful to four-cylinder engines. Nothing more and nothing less, the Mazda MX-5 has always been about striking the perfect balance between lightweight construction and just the right amount of power. However, little did we know that Mazda’s engineers once made a V6 prototype as a passion project.

Enthusiasts have been craving a bigger engine for as long as we can remember, and the aftermarket scene has promptly delivered with everything from V8 swaps to even a bonkers V12 heart transplant. Mazda didn’t go that far with the Miata it secretly built some 20 years ago, deciding instead to use a 2.5-liter V6.

The surprising disclosure comes from Christian Schultze, the company’s head of research and development in Europe. Speaking with Dutch magazine AutoRAIMazda’s higher-up revealed the one-off MX-5 wasn’t a company-backed official project but rather something the engineers quietly built after hours.

After they shoehorned the V6 into the engine bay, they stumbled upon a problem: packaging. The six-cylinder sat too high and ruined the car’s design, though it’s unclear whether they used an NB or NC Miata. Twenty years ago would mean the six-cylinder MX-5 was conceived in 2006, right around the time the roadster transitioned from its second to third generation. Given that the NC was the largest of all Miata generations, we reckon that’s what the engineers used.

Although the outcome wasn’t “visually appealing,” Schultze said the V6-powered prototype was “definitely interesting” to drive. We do wonder how a larger, heavier engine affects the driving experience, as the weight distribution must have suffered. Mazda has always prioritized a perfect 50:50 balance, and stuffing in a heavier engine inevitably took its toll, with the nose ending up heavier.

It’s unclear how much power it had, but the 2.5-liter displacement hints at a K-series engine. The KL-DE in the larger MX-6 had 200 hp on tap, which would’ve given it a 30-hp advantage over the four-cylinder 2.0-liter engine used in the NC1-generation Miata. Of course, there were other advantages to having a V6 beyond just peak power, but it wasn’t meant to be.

It’s reasonable to assume that Mazda had the know-how to fit the V6 under the hood properly, but it would’ve required too much reengineering. That would have added costs, which are always a sensitive subject for low-volume products such as a sports car. Even if a V6 had physically fit, a production car still needed to pass safety and emissions regulations, which would’ve added even more expense.

In 2026, the Miata still hasn’t cracked the 200-hp barrier. The most powerful MX-5 of them all is a Japan-only 12R special edition with 197 hp. We’ll likely have to wait for the next-generation model to see the horsepower figure start with a “2.” The ND is already over a decade old, so Mazda has had plenty of time to max out its platform by now.

Motor1’s Take: As with other long-running automakers, Mazda must have quite a few stories to tell. With the MX-5 being the company’s halo car and having followed a strict formula for decades, it’s understandable why there’s resistance to throwing the rulebook out. It’s a recipe that has worked since the NA generation arrived in 1989.

While a bigger engine would be nice, the financial reality is that Mazda remains a relatively small automaker and can’t afford to experiment with the MX-5. With even stricter emissions regulations looming, an engine with more than four cylinders is highly unlikely. We should just be thankful the Miata is still alive and kicking in 2026, especially as the BMW Z4 is about to drive off into the proverbial sunset.