IEEE Spectrum's Top 10 Looks Beyond Hybrids
April 11, 2007: Source—Top 10 Tech Cars
The hulking Yukon Hybrid from GM works its technology for a 20 percent increase over the conventional Yukon—to reach 22 mpg.
The editors of IEEE Spectrum Magazine just issued their fifth annual list of top ten tech cars, according to “the most ingenious” use of technology. Based on the list, almost all of that ingenuity is being used for environmental benefits.
John Voelcker, auto journalist and friend of HybridCars.com, does a great job every year with the article. This year, the top of the list slants significantly toward the exotic and futuristic with electrics, hydrogen-powered, and plug-in concepts. Only one showroom-destined hybrid is on the list: the GMC 2008 Yukon Hybrid. John writes:
Today, the state of the art has passed beyond hybrids to technologies that seemed dead or ridiculously exotic even a year ago: pure electric-drive cars, including fuel-cell vehicles; and plug-in hybrids, which give the option of charging the hybrid’s batteries directly from a wall socket. Don’t look for such cars in showrooms any time soon, but notice that some pretty specific ideas about how they will enter the market are starting to emerge.
The hulking Yukon Hybrid from GM works its technology for a 20 percent increase over the conventional Yukon—to reach 22 mpg. How does it manage to nudge the SUV’s mileage to a semi-respectable level?
According to chief engineer Tim Crewe, 70 percent of the total effort involved in designing and testing the system went toward control logic. That logic analyzes hundreds of inputs every 10 milliseconds, including vehicle load, engine operations, battery parameters, and the temperatures in the high-voltage electric components. Depending on vehicle speed and power requirements, one motor-generator may assist the engine, or provide regenerative braking, with the other shut down for greater efficiency. Or both motors can provide boost or braking simultaneously. And the combination of planetary gear sets and electric motors smoothes the shifting among modes, so that engine speed can stay constant even as it varies the electric power delivered to the battery or drive wheels.
The full Top 10 list includes: Tesla 2007 Roadster, Honda Fcx/Concept, GMC 2008 Yukon Two-Mode Hybrid, FIAT 2007 Siena Tetrafuel, Volkswagen 2007 Golf GT TSI, Chevrolet Volt/Concept Car, Subaru 2007 Outback 2.5XT, Audi 2008 R8, BMW 2008 5-Series, and Chrysler 2007 Sebring.