GM to use CVT transmissions
The company is also exploring the use of turbochargers on smaller engines.
Getting superior mileage is key to winning over U.S. drivers to the latest wave of small cars that began with the launch of the Cruze this year and continues with the arrival of the four-seat Spark in the first half of 2012.
GM will have to improve the mileage on these models by at least 10 percent by the next full-model change, said Sohn Dongyoun, vice president of engineering at GM's global small- and minicar development team at GM Daewoo. CVTs offer an easy, quick fix, he said.
General Motors offered CVTs in three vehicles, the Saturn Ion coupe and Vue SUV and the Opel Astra small car, for three years but dropped the transmission at the end of the 2005 model year.