Less than a year after pulling its mild hybrids off the market, General Motors announced that it will bring back the less expensive hybrid technology. According to Larry Nitz, G.M.’s executive director of hybrid and electric powertrain engineering, the carmaker is prepared to roll out the next generation of its mild hybrid technology on at least one mid-sized sedan next year. The new powertrain reportedly will be equipped with a lithium ion battery supplied by Hitachi, and will provide about four times as much power and will be 24 percent smaller and 40 percent lighter than previous mild hybrid battery packs.
Unlike a full hybrid system, a mild hybrid system cannot propel a vehicle on electric power alone. It only shuts off the gasoline engine when the car stops and then uses the batteries to restart the engine. The electric motor also provides a boost during acceleration.
When the Saturn Aura won “Car of the Year” at the 2007 North American Auto Show, and that model had a mild hybrid variant, it looked like G.M. might be getting ready to launch hybrids into its mainstream lineup. G.M. would eventually offer five mild hybrid vehicles: the Aura; the Saturn Vue Green Line; the Chevy Malibu hybrid; the Chevy Silverado hybrid; and the Buick Lacrosse EcoHybrid, which was sold only in China. But across all five models, the GM never produced more than about 15,000 vehicles per year and by summer of 2009, all had been canceled. (Beginning in 2009, Chevy switched the Silverado hybrid to a full-hybrid, its so-called “two-mode” hybrid system.)
Starting and Stopping
In June 2009, G.M. cited low sales as the reason for cutting the Malibu Hybrid.
When the Malibu Hybrid first launched, critics said the car didn’t deserve the hybrid name, because it only managed a 2-mpg jump to 24 in the city and 32 on the highway. The 2009 Malibu Hybrid managed a more respectable 4-mpg boost over the base-level Malibu. (Last year, G.M. dropped the entire Saturn brand, effectively killing the Saturn mild hybrids.) Regardless, consumers weren’t convinced to buy G.M.’s mild hybrid vehicles from either a value or fuel economy perspective. The Saturn Aura sold in the same price range as full hybrids like the Prius and Civic, which offered roughly 15 mpg more fuel economy. In order for G.M.’s mild hybrids to be competitive, it became clear that costs would have to be brought down and fuel economy gains would have to go up.
Back to the Drawing Board
From what little we know, G.M.’s new mild hybrid system seems more convincing. With increased torque and fuel economy gains of 15-20 percent, the outlook is significantly brighter than its predecessor. The new system is designed to be more versatile, allowing G.M. to attach it to a broader range of vehicles—including those with six-cylinder engines.
It’s not yet known which models might initially be fit with the system. Last year, Dan Hancock, vice president of powertrain engineering, indicated to reporters at the Geneva Auto Show that G.M. could be preparing to produce as many as 100,000 mild hybrids per year. That might just be a start. As federal CAFE standard gradually rises to 34.9 mpg by 2016, all automakers will be forced to find whatever means possible to increase fuel efficiency for all vehicle segments.
Given its investment and experience with mild hybrids, it makes sense for G.M. to bring back a new and improved version of the technology as a cost-effective way to increase fuel efficiency by 15 to 20 percent. However, it remains to be seen how G.M. will find a way to convince consumers to spend more money on these mild hybrids—especially because the cutting edge of green technology has shifted even beyond full hybrids to plug-in cars, such as G.M.’s own Chevy Volt. The key will be pricing: If G.M.’s new mild hybrids cost only a couple hundred dollars more than similar conventional models, while offering 20 percent better fuel economy, then the company might finally have the right formula for mainstream green.