car, maximizing interior passenger and luggage space, as well as providing a good noise and vibration emissions profile. However, it is questionable whether or not the inherent disadvantages of the Wankel engine allow the usage of the Wankel engine as a range extender for passenger cars. In 2010, Audi unveiled a prototype series-hybrid electric car, the A1 e-tron. It incorporated a Wankel engine with a chamber volume Vk of 254 cm³, capable of producing 18 kW at 5000/min. It was mated to an electric generator which recharged the car's batteries as needed and provided electricity directly to the electric driving motor. The package had a mass of 70 kg and could produce 15 kW of electric power. In November 2013 Mazda announced to the motoring press a series-hybrid prototype car, the Mazda2 EV, using a Wankel engine as a range extender. The generator engine, located under the rear luggage floor, is a tiny, almost inaudible, single-rotor 330-cc unit, generating at 4,500rpm, and maintaining a continuous electric output of 20 kW. Mazda announced that they would launch the MX-30 R-EV fitted with a Wankel engine range extender in March 2023. Eventually, the car was presented at the Brussels Auto Show on 14 January 2023. The car's Wankel engine is a naturally aspirated single-rotor unit with a chamber volume Vk of , a compression of 11.9, and a rated power output of . It has petrol direct injection, exhaust gas recirculation, and an exhaust-gas treatment system with a TWC and a particulate filter. According to auto motor und sport, the engine is Euro 6d-ISC-FCM-compliant. Motorcycle applications The first Wankel-engined motorcycle was an MZ-built MZ ES 250, fitted with a water-cooled KKM 175 W Wankel engine. This was followed by an air-cooled version, called the KKM 175 L, in 1965. The engine produced at 6,750rpm, but the motorcycle never went into series production. Norton In Britain, Norton Motorcycles developed a Wankel rotary engine for motorcycles, based on the Sachs air-cooled rotor Wankel that powered the DKW/Hercules W-2000 motorcycle. This two-rotor engine was included in the Commander and F1. Norton improved on Sachs's air cooling, introducing a plenum chamber. Suzuki also made a production motorcycle powered by a Wankel engine, the RE-5, using ferroTiC alloy apex seals and an NSU rotor in a successful attempt to prolong the engine's life. In the early 1980s, using earlier work at BSA, Norton produced the air-cooled twin-rotor