GM Showcases “Dual Hybrid” Technology

August 24, 2006 by Jeff Shepard

General Motors Corp. (GM) is unveiling what it is calling its "dual-hybrid" technology, consisting of two electric motors, a V-8 engine that can work on only four cylinders, a really smart computer, and a four-speed transmission that joins them into one package. GM claims that it will soon make pickup trucks or big sport utility vehicles as fuel efficient as some cars.

The technology, showcased with GM's future engines and powertrains this week at the company's proving grounds northwest of Detroit, will start showing up in the 2008 model year with the Chevrolet Tahoe SUV. It will be available on the GMC Yukon and Cadillac Escalade SUVs and the Chevrolet Silverado pickup — GM's top-selling vehicle — later that year.

GM says the hybrids, similar to those now in use in the transit buses of 39 cities, are so versatile that they will boost fuel economy by 25% over the current SUVs and pickups. For the two-wheel-drive Tahoe, which now gets an average of 18.3 miles per gallon in combined city-highway driving, that means nearly 23 mpg. Figures for city and highway driving haven't been calculated yet, but Tim Grewe, GM's Chief Engineer for rear-wheel-drive powertrain hybrids, said there will be a significant improvement. "We give you the highway economy and we give you the city economy while maintaining SUV performance."

The dual hybrids, developed jointly by thousands of engineers with GM, DaimlerChrysler AG and BMW AG, also will be placed in the Dodge Durango and BMW vehicles. Prices on the GM vehicles haven't been set, Grewe said, but the company plans to make them competitive, similar to a $2,000 premium on the hybrid version of the Saturn Vue.

As automakers continue developing hydrogen fuel cells, Grewe said the future of fuel-efficient engines will include a combination of smaller diesels, gasoline engines and hybrids. GM has teams of engineers working to make all the technologies more fuel efficient and environmentally friendly, engineers said Thursday.