Weichai Power Co., Ltd. is a Chinese developer and manufacturer of diesel engines in Weifang, Shandong in the People's Republic of China.

[5] In 2009, Weichai bought French marine engine manufacturer Moteurs Baudouin.

[1][8] Since 1999, Weichai Group has partnered itself with Bosch, an engineering company based in Gerlingen, Germany, to share research and development on technologies such as fuel cells and common rail fuel-injection systems.

Both companies plan to develop new electric vehicle technology, as Weichai has planned since 2010 to focus on new energy options and has invested approximately $550 million in research and development of electric, hybrid and hydrogen fuel cell engines.

This diesel engine has 53.09% thermal efficiency as verified by Technischer Überwachungsverein, an international testing body.