Isuzu Motors Ltd. is a Japanese car, commercial vehicle and heavy truck manufacturing company, headquartered in Tokyo. In 2005, Isuzu became the world's largest manufacturer of medium to heavy duty trucks. It has assembly and manufacturing plants in the Japanese city of Fujisawa, as well as in the prefectures Tochigi and Hokkaidō. Isuzu is famous for producing commercial vehicles and diesel engines. By 2009, Isuzu had produced over 21 million diesel engines, which can be found in vehicles all over the world. Isuzu diesel engines are used by Renault-Nissan Alliance and General Motors.