The Mazda Roadpacer AP (Anti-Pollution) is a full-size sedan that was sold by Mazda in Japan between 1975 and 1977, although the last car was not sold until 1979. It was based on the Australian Holden HJ and HX series Premier. Premiers were shipped to Japan without engines or transmissions, and Mazda fitted a 1.3-liter 13B Wankel engine into the bay. The Roadpacer AP has the distinction of being the only General Motors product ever to be fitted for production with a rotary engine. The engine produced but just of torque, meaning the Roadpacer performed rather poorly as it weighed . The Roadpacer was introduced to compete with large Japanese flagship sedans Toyota Century, Nissan President, Isuzu Statesman de Ville, and the Mitsubishi Debonair. The Roadpacer's platform was the shorter version of the one used by Isuzu for the Statesman de Ville. The Roadpacer was conceived just years before Mazda entered into an engineering partnership with Ford, which materialized at around the same time the Roadpacer went on sale. The 13B produced less power than the Red series motors that powered the equivalent Holdens, and significantly less torque, meaning performance was restrained with a top speed, poor acceleration and terrible fuel consumption. Contemporary reports suggest 9 mpg (26 L per 100 km). The three-speed automatic transmission with a steering column shift lever was sourced from Jatco and was shared with the LA series Mazda Luce. The vehicle was not in compliance with Japanese regulations concerning engine displacement and exterior dimensions, and was classed in the mid-size car segment, while the engine displacement placed it in the lower annual road tax brackets. If the car was recognized as being for business use as an executive company car, the road tax bill was very minimal. While the Holden HJ Premier itself was well equipped, Mazda decided to add more. Gadgets of note include a central locking system that activated when the car hit , a chime system that activated at , a dictation system and a stereo able to be controlled from both front and back seats. The interior was offered with a choice of velour upholstered bucket seats and a center console for the front passengers or a split front bench seat. The Roadpacer was built only for the Japanese market, and certain aspects concerning its lack of speed become evident once its realized that urban two-way streets are usually zoned