Mazda Planning Two-Rotor Engine for America

The CEO says a one-rotor setup wouldn't be powerful enough for customers in the United States.

Mazda Iconic SP Concept

Adrian Padeanu

By: Adrian Padeanu

Dec 4, 2024 at 3:31am ET

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Mazda is serious about keeping the rotary engine alive for the long haul. After launching the MX-30 e-Skyactiv R-EV in early 2023 with its 830-cc rotary engine serving as a generator, it reinstated the dedicated rotary engine team at the beginning of 2024. Some 36 engineers are working on making "attractive cars that excite customers," with a sports car molded after the Iconic SP concept officially being considered.

During a new interview with Automotive News, CEO Masahiro Moro shared more details about the rotary engine's future. Mazda's top brass admitted that it's a "significant challenge" to develop an engine that passes increasingly stricter emissions regulations in the United States. However, the Japanese automaker is "very close" to reaching its objective with a single-rotor setup like the MX-30 e-Skyactiv R-EV, a small crossover not sold in America. Due to abysmal sales, the purely electric version was dropped from the US after the 2023 model year.

Moro argues that a single-rotor engine wouldn't cut it for America, where more power is needed, so Mazda is engineering a two-rotor setup. The Iconic SP concept had a longitudinally mounted two-rotor system, but as with the crossover where the engine sits transversally, it didn't drive the wheels. Instead, it acted as a generator to charge the battery pack, which powered an electric motor.

The system output was rated at 365 horsepower in the sports coupe, which had a nearly perfect 50:50 weight distribution. The car tipped the scales at 3,197 pounds (1,450 kilograms) and measured 164.5 inches (4180 millimeters) long, 72.8 inches (1850 millimeters) wide, and 45.2 inches (1150 millimeters) tall, with a wheelbase of 102 inches (2590 millimeters). Mazda said it intentionally made the Iconic SP larger to generate a bigger splash but could downsize the sports for production to the size of a Miata.

"We have tested with the single rotor. The next phase will be moving to two. The rotors spin separately in different chambers with one shaft. We need to generate more electricity. Two rotors will generate more power, which is more suitable to US market characteristics."

The part where Mazda's CEO says the engine must "generate more electricity" implies the two-rotor setup wouldn't be mechanically connected to the wheels. Consequently, a production version of the Iconic SP or another type of vehicle would pretty much behave like an EV.

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On a related note, Moro also discussed the recently announced Skyactiv-Z engine, hinting it will skip turbocharging. Debuting on production cars in 2027, the new gas engine is the "ultimate" ICE for Mazda, an all-new powertrain designed to meet even the stricter regulations planned for the next decade. It'll replace both the Skyactiv-G and the Skyactiv-X, which, despite the hype about delivering diesel-like efficiency with fewer emissions, never really caught on.

"Normally aspirated engines would have to decrease output by 30 percent to comply with such stringent standards. But this engine [Skyactiv-Z] defies that usual theory and keeps output while delivering outstanding environmental capability."

The Rotary Engine Lives:

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The Rotary-Electric Mazda Iconic SP Concept Could Save the Sports Car