General Motors Vice Chairman and Chief Technology Officer Tom Stephens has elected to retire effective April 1, after a 43-year engineering career with the automaker. As CTO, Stephens led the company’s product technology arm, working to identify and develop advanced technologies while building closer relationships with external and internal technology partners. His successor will be named later. Stephens, 63, served in a number of positions at GM, including Vice Chairman, Global Product Operations; and Executive Vice President, Global Powertrain and Global Quality. He began his GM career in 1969 as an hourly employee at the Chevrolet Engineering Center in Warren, MI, under the University of Michigan Student Co-op Program. An "engine guy" to the core, Stephens' career highlights include leading the development of the Cadillac Northstar V8, GM’s premier DOHC performance engine. He also spearheaded the creation of GM’s advanced propulsion technology strategy, which guided the company’s development of a wide range of advanced engine technologies, hybrid vehicles, and the Chevrolet Volt. Stephens was elected to the National Academy of Engineering in 2007 for his contributions to powertrain engineering.