At GM, it's the testing o' the green.

ARLINGTON ? Workers at the Old World GM truck plant go green today. For two days starting this morning, the workers will practice building hybrids as General Motors Corp. prepares to offer the industry's first full-size hybrid sport utility vehicles this fall. The vehicles are true hybrids powered by small V-8 engines and electric motors that should provide a 25 percent improvement in fuel economy ? to about 20 miles per gallon city and 25 on the highway.