General Motors' Bob Lutz, a strong advocate for the company's Chevy Volt, plans to retire by the end of the year.

Lutz is leaving during a year when GM will have to fight hard for its survival. The automaker has said that it still plans to launch the Volt, a plug-in hybrid-electric car, in 2010 despite its financial woes.

Lutz, who has been the vice chairman for global product development, will become a senior advisor starting on April 1, the company said Monday. Thomas G. Stephens, GM’s current executive vice president for powertrain and quality, will take over Lutz’s job.

Lutz has been a big supporter of the Volt, which GM is banking on to set itself apart from other automakers who plan to introduce their own plug-in hybrid electric vehicles around the same time. He also is known for controversial statements, such as the one expressing his disbelief in global warming. Earth2Tech has a good post listing some revealing and funny quotes by Lutz.

The outspoken man has done his part in pushing GM to recognize the importance of developing alternative, fuel-efficient cars. The rest is up to the company to make good use of the federal loans to return to good financial health.