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Hot Hybrid Cars Coming from General Motors


By Todd Kaho
Saturn On Stage

What a difference a year makes. After unveiling the Volt concept at the 2007 North American International Auto Show in Detroit, General Motors kept the pedal down, rolling out three more versions of the E-Flex architecture, launched the Two-Mode Hybrid system in full-size SUV and pickup platforms, and announced a Two-Mode front drive version coming for the Saturn Vue Green Line with a plug-in to follow. In a little over one year, GM has become a dominant force in the hybrid market and a huge proponent of electric drive.

While much of its news involves long range goals and product, GM hasn’t forgotten about the short game. The current product mix includes economical mild hybrid systems in the Saturn Vue Green Line, Saturn Aura Green Line, and Chevy Malibu. These relatively simple belt-alternator-systems can’t drive on electric power alone, but the electric assist and stop/start function help to boost fuel economy between 10 to 25 percent. GM views this technology as a way to bring high value systems to a wide range of buyers at a very affordable price point. After all, the Vue Green Line lists for $25,995 while the Aura and Malibu are both $22,790.

Next Gen Hybrid Cutaway

GM currently has over 1,600 engineers, including GM employees and contract workers, working on electric vehicle technology worldwide. The announcement of a second generation version of the belt-alternator-starter hybrid system used in the Vue, Aura, and Malibu is an interesting development.

General Motors Chairman Rick Wagoner outlined the game plan for the new system at the Geneva Auto Show in early March. “The new system is another important step in our broad-based strategy to reduce vehicle fuel consumption and emissions,” says Wagoner. “In order to have real impact in reducing oil consumption, oil imports, and CO2 emissions, advanced technologies must be affordable enough to drive high-volume applications. We plan to roll out this next-generation hybrid technology globally, across all our brands and regions, starting in 2010 in North America, and we expect that volumes will eventually exceed 100,000 units annually.”

Saturn Aura Hybrid Cutaway 1

Though similar in layout, the Next-Generation Hybrid system is much more robust … in fact three times more powerful. In place of the nickel-metal-hydride (NiMH) battery used in current models, the new system’s additional boost will be supplied by a smaller, lighter lithium-ion (Li-Ion) battery. This battery will be 24 percent smaller, 40 percent lighter, and provide 33 percent more power. GM is working with Hitachi Vehicle Energy Ltd., a subsidiary of Tokyo-based Hitachi Ltd., as the supplier for the new lithium-ion pack.

GM engineers describe the new higher voltage hybrid system as the same basic architecture as the current system on steroids. It looks beefier, with a much larger motor-generator driven by a bigger belt, though it all fits in the same space. The new motor-generator is said to produce roughly 15 kW of power.

Ecotec Engine

Performance of the 2.4-liter four cylinder hybrid matches that of a naturally aspirated 3.6-liter V-6. In addition to offering more power, voltage, and electric boost for better fuel economy and acceleration, the new system also benefits from improved regenerative braking to recapture some of that energy. Fuel efficiency and lower emissions have been optimized by programming in brief electric-only propulsion to move away from a stop, extending fuel cutoff during deceleration, turning the engine off at idle, and extending the regenerative braking function. Overall fuel economy gains are expected to come in at an average 20 percent improvement over the non-hybrid version, depending on the vehicle.

GM will also utilize a new advanced six speed automatic transmission to maximize efficiency in some applications. Execs are quick to point out that the Next-Generation Hybrid system is intended to compliment GM’s Two-Mode Hybrid, offering many of the same benefits at a much lower price point. Perhaps most important is that the Next Generation Hybrid can be implemented across a wide product portfolio. It works quite well in a turbocharged and downsized engine scheme, offsetting turbo lag at low rpm. GM has also hinted at potential applications with biofuels and diesels.

To say that General Motors has momentum in hybrids and electric drive is an understatement. The company has pledged to introduce no less than 16 new hybrid production models in the next four years. The current lineup will include eight hybrid models by the end of 2008 and nine worldwide … representing quite a bit of momentum, indeed.

Want to know more about coming hybrid cars? Be sure to check out these articles on GreenCar.com:
BMW EfficientDynamics Hybrid Car Concept
Plug and Play Prius Hybrid Car Runs on Electricity
Toyota’s A-BAT Hybrid Electric Pickup

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