DETROIT – General Motors Ventures LLC said it is investing $6 million in Proterra Inc., a leading maker of zero-emission commercial transit buses.

GM Ventures is part of an investment group, led by venture capital firm Kleiner Perkins Caufield & Byers, that will invest a total of $30 million in the bus manufacturer.

Proterra’s EcoRide BE-35 battery electric bus is averaging up to 24 mpg (diesel equivalent) in service, a more than 600-percent improvement over a typical diesel bus. Using technology developed by Proterra, the lightweight, composite-body bus recharges in about 10 minutes.

“This equity investment further demonstrates GM’s commitment to electric propulsion and supports our commitment to identify and invest in technology solutions that help advance the global transportation industry,” said Jon Lauckner, president of GM Ventures. “While this investment will help Proterra commercialize its electric bus and fast-charging technology, it also helps to address the future challenges of urban mobility.”

Proterra Inc. was founded in 2004 and is currently manufacturing buses in a temporary plant in Greenville, S.C., near Clemson University International Center for Automotive Research. Proterra’s TerraVolt energy storage system consists of 54-72 kWh lithium titanate battery packs that recharge in 10 minutes using the company’s roof-mounted Fast Fill recharging system.

Three EcoRide BE-35 buses are currently in a test fleet near Pomona, Calif., with additional buses to be added, and new buses and charging stations are also headed to San Antonio and Tallahassee, Fla., later this year. This investment allows Proterra to complete federal validation testing of its bus, roll out additional pilot fleets and complete initiatives to significantly reduce costs and increase volume production at its Greenville, S.C., manufacturing plant, which will have the capacity to produce 400 buses annually.