DETROIT - General Motors will put its Displacement on Demand cylinder deactivation on three mid-sized SUVs for the 2005 model year.
The vehicles are the GMC Envoy XL, GMC Envoy XUV and the Chevrolet TrailBlazer EXT. The system will be a standard feature in the vehicles' optional 5.3-liter, V-8 engine.
GM says cylinder deactivation will improve fuel economy by 8 percent, based on EPA testing. GM spokesman Dave Roman says the automaker projects that about 100,000 engines with the system will be sold in model year 2005. According to Chevrolet data, the TrailBlazer EXT equipped with the V-8 gets 15 mpg in the city and 19 mpg on the highway. That means the system would boost fuel economy to 16.2 mpg city and 20.5 mpg highway.
Using electronic controls, the GM system uses only half an engine's cylinders under most normal driving conditions by closing intake and exhaust valves. All cylinders operate when more power is needed, such as in rapid acceleration.