If only General Motors chairman Rick Wagoner had driven a Chevrolet Silverado Hybrid to Washington last November instead of flying via company jet. A two-wheel-drive version of this pickup could have completed the Detroit-to-D.C. journey on one tank of regular, thereby hinting to our elected representatives that GM gets it. In his remarks before Congress, the now former chairman might have noted that his vehicle of choice was not some distant development but instead a real, ready-for-market, cowboy Cadillac steeped in advanced technology.
After huzzahs from the Michigan contingent subsided, Wagoner could have added that neither Honda nor Toyota has a full-size pickup capable of performing a good day's work and matching the Silverado Hybrid's 20-21 combined mpg. His punch line could have been that the Volkswagen New Beetle and the Scion tC - two subcompacts that cringe at the prospect of towing anything - score 20 mpg, the same as a four-wheel-drive Silverado Hybrid, in EPA city mileage tests.
Instead of orchestrating good news in D.C., GM quietly launched the Chevy Silverado and GMC Sierra Hybrids in San Antonio, where Toyota builds Tundra pickups and gasoline was available for as little as $1.66 per gallon. Playing along with GM's gambit, I explored the full scope of hybrid pickup truck fuel efficiency. During a 200-mile trip on Interstate 35, I averaged 10 mpg towing a 23-foot Sea Ray boat on a tandem-axle trailer - a 5400-pound payload. While balloon-footing a Silverado Hybrid on a thirty-mile tour of greater San Antonio, I recorded just over 25 mpg.
GM's two-mode hybrid system could be the most complex powertrain ever produced. A 6.0-liter V-8 with Atkinson-cycle and cylinder-disabling technologies is teamed with two 80-hp AC motors and three planetary gearsets to provide two continuously variable ranges and four fixed ratios. When gently accelerating from a stoplight, it's possible to reach 30 mph with the engine napping. At steady highway speeds, half of the cylinders take a break. During a flat-out run from rest to the 99-mph governed limit, acceleration momentarily levels out at 38 and 73 mph so the system can smoothly engage higher ratios.
The 300-pound, 300-volt nickel-metal-hydride battery pack stashed under the back seats is charged by a mix of regenerative braking and electrical current provided by one motor operating as a generator.