New energy-efficient light-rail cars were unveiled Wednesday, a preview of the ones that will run on the Central Corridor line when it opens in 2014 between St. Paul and Minneapolis.

The cars are 6,000 pounds lighter than those running on the Hiawatha line between Minneapolis and Bloomington. The lighter vehicles will use less electricity and feature LED internal lighting instead of fluorescent lighting, which uses more energy.

Forty-seven cars will be built for the Central Corridor, which along with a future Southwest Corridor route will be dubbed the Green Line. Another 12 cars will be used on the Hiawatha line, which will become the Blue Line.

The additional vehicles, which cost $3.3 million each, will allow Metro Transit to operate three-car trains during peak times.