GM to introduce a new iteration of mild-hybrid technology in 2011
Although temporarily relegated to back burner status during the past couple of years, the mild-hybrid technology that last appeared on a General Motors U.S. product in 2009 is set to make a comeback starting late next year. The arrival of what will be a new and more-powerful variation on the original "BAS" -- for belt-alternator-starter -- theme was confirmed by Larry Nitz, GM's executive director of hybrid and electric powertrain engineering, at this week's Center for Automotive Research Management Briefing Seminars.
While presenting few speciflcs, Nitz did confirm that GM plans to introduce this new Gen II mild-hybrid setup during the third quarter of 2011. It's currently slated to appear on at least one mid-sized sedan in the U.S. as well as be used on GM vehicles sold in China. The Chinese-spec Buick LaCrosse currently is available with GM's original mild hybrid package. Like that first-generation setup, this new-and-improved version incorporates start-stop circuitry as well as an electric motor that will be able to provide an additional measure of temporary assist to the gasoline engine.
Unlike its predecessor, the Gen II system features a more efficient overall design that includes both a significantly more powerful 100V Lithium-ion (Li-ion) battery in place of the earlier 36V nickel-metal hydride (Ni-MH) unit and adds regenerative braking to the mix. While the gasoline side of the equation will continue to be a small four-cylinder Ecotec engine, it will be paired with a new six-speed automatic transmission instead of the four-speed used previously. GM expects this new package to generate about a 20-percent gain in fuel efficiency compared to a conventional gasoline engine -- roughly double that of GM's first BAS system.
Nitz also indicated that GM's even-more advanced but considerably more costly Two-Mode Hybrid system that actually does permit a vehicle to operate on pure electric power also has a future. While large pickups and SUVs remain the most natural home for Two-Mode technology (it's currently available in the Cadillac Escalade Hybrid, Chevrolet Silverado/Tahoe Hybrids and GMC Sierra/Yukon Hybrids) exactly when, where and in what a next-generation version may appear remains to be seen.