Two-Mode Hybrid System: GM's Larry Nitz on Lessons Learned

By John Voelcker

John Voelcker

Senior Editor BIO

John is Senior Editor for High Gear Media. In addition to news coverage and new car reviews, John creates and oversees all editorial for High Gear's... More

LATEST ARTICLE
Do Electric And Natural-Gas Cars Compete Against Each Other?
We've been thinking a lot about natural-gas fueled vehicles, for reasons that will become clear in... Read More

• #4LEADERBOARD RANK
• 2901ARTICLES CONTRIBUTED
• 1950COMMENTS POSTED

1,883 views Jun 15, 2010

Follow John

Add to circle

2010 GMC Yukon Hybrid

Enlarge Photo

The Two-Mode Hybrid system for large sport utilities and trucks hasn't exactly set the world on fire.

In 2006, General Motors, Daimler and Chrysler (then a single company) announced a partnership, soon joined by BMW, to develop the Two-Mode Hybrid system for large rear-wheel drive vehicles.

But Daimler and Chrysler split, two of the partners declared bankruptcy and were reconstituted with U.S. government funds, and the once-promising four-way partnership has been dissolved.

GM goes solo

Now GM is the sole proprietor (and largest user) of the Two-Mode system. Yet last year, GM sold just 8,820 Two-Mode Hybrids, the bulk of them full-size hybrid sport utility vehicles from Cadillac, Chevrolet, and GMC. Toyota, meanwhile, sold almost half a million Prius hybrids globally last year.

GM's Larry Nitz, at the Hybrid Development Center in Troy, Michigan, in April 2006

Enlarge Photo

In March, Chrysler's Ram Truck brand (nee Dodge) killed its Ram Hemi Hybrid pickup truck, which was to use the Two-Mode system.

BMW and Mercedes-Benz use the Two-Mode only in small numbers of their X6 and ML crossovers, and are moving away from using the Two-Mode, preferring instead to evolve their own mild hybrid system.

With all that water under the bridge, we were curious how GM viewed the Two-Mode Hybrid project these days--and what lessons the reconstituted company felt it had learned from the project.

We spoke to Larry Nitz, who is GM's executive director of electric and hybrid powertrain engineering. He said the company's intent "was not to sell huge amounts of these in the early stages."

Not aiming for high volume

Instead, Nitz said, "the intent is to learn" how they're used and how they hold up to real-world conditions. And the same may apply to the second generation of the system as well, though perhaps in slightly higher quantities.

It'll only be "by the third or fourth generation that the costs get lower," Nitz said, and that's when GM can go "much higher" in production volumes--perhaps just in time to meet the stringent fuel economy requirements that come into effect for 2016 and thereafter.