General Motors is dividing its new powertrains into three categories -- image, high-feature, and high-value, said Tom Stephens, group vice president of GM Powertrain at a media briefing at the automaker's Milford Proving Grounds. GM's powertrain brand names include North-star, Vortec, Ecotec, VTi and Hydra-Matic. Image powertrains are directed at fewer than one percent of the market that make a vehicle purchase based mainly on power and performance, according to Stephens. The 5.7-liter V-8 in the Chevrolet Corvette Z06 is an example of such an engine. GM says it will build its first 12-cylinder engine since 1937 for future Cadillac vehicles. The V-12, 7.5-liter engine will pump out more than 500 horsepower. The company won't say how much more than 500 horsepower, when it will go into production, or what Cadillac vehicle will have one. Under the high-feature category is a new family of dual overhead camshaft V-6 engines with a displacement spread of 2.8-3.6 liters. The first version debuting next summer will be a 3.6-liter V-6 producing 255 horsepower. In the high-value category, GM is expanding its lineup of overhead valve V-6 engines to include displacements up to 3.9 liters. They're designed to run smoother with improved fuel economy. A 3.5-liter version will debut in the 2004 Chevrolet Malibu. In addition, the company plans to introduce engines with displacement on demand (DOD) tech-nology in the 2005 calendar year. GM estimates DOD will improve fuel economy by up to 20 per-cent. A V-6 engine with the technology starts on all six cylinders but under light load or cruising conditions it operates on just three. When more power is needed, the other three cylinders are reactivated. GM said it also plans to produce five- and six-speed automatic transmissions.