GM Korea Co., the South Korean unit of U.S. automotive giant General Motors, on Thursday unveiled its diesel-powered Malibu mid-size car that it said promises class-leading driving characteristics and fuel economy. The car sold under the Chevrolet badge sports a 2.0 liter "Ecotec" turbo diesel from Germany, mated to an optimized six-speed automatic transmission made by Aisin Seiki Co., one of the largest car parts makers in the world.