Fuel Efficiency to Be Increased on Some GM Trucks
General Motors Corp. will announce today that it will install more-fuel-efficient V-8 engines in some of its light trucks starting in 2004, increasing mileage by as much as 25%, officials said.
The new engines, part of GM’s efforts to maintain its edge in truck fuel efficiency over rival Ford Motor Co., resurrect “displacement-on-demand” technology, which automatically shuts off half of the V-8’s cylinders, temporarily turning it into a more efficient four-cylinder, when the trucks are cruising at a constant speed or carrying a light load. During acceleration or when pulling a heavy load, all eight cylinders do the work.
GM plans to produce more than 150,000 of the V-8 engines in 2004 and increase output to nearly 1.5 million units annually by 2007.
GM’s light-truck fleet, weighted by sales, averaged about 21 miles per gallon last year. The new engines would be put in its larger vehicles, which are less fuel-efficient, such as the Chevrolet Suburban full-size SUV, which gets 14 to 18 miles per gallon.
Sam Winegarden, GM’s chief engineer of Vortec V-8 engines, said the split-second transition from V-8 to a four-cylinder is unnoticeable and vastly superior to when GM’s Cadillac division briefly tried a displacement-on-demand engine in 1981.
That engine, which shifted between a V-8, a six-cylinder and a four-cylinder, depending on the driving conditions, lasted only about one model year because it shook uncontrollably and the technology was much more costly.
“The capability of the computer in the early 1980s wasn’t sophisticated enough,” Winegarden said. “Back when Cadillac tried it before, the transition wasn’t always seamless. The fuel economy gains were pretty substantial however.”
GM officials have been annoyed by Ford’s efforts to portray itself as an environmental leader and have taken more steps to point out their own contributions to raising fuel efficiency and cutting vehicle emissions and pollution.
“We clearly have got the lead there, and we intend to keep that,” Winegarden said.
Meanwhile, pressure is mounting on the U.S. government from environmental groups to raise the required fuel efficiency to the same level as cars. President Bush’s energy plan, announced last week, said the government will reexamine federal fuel economy standards, with an eye toward raising them “without negatively impacting the U.S. automotive industry.”
Winegarden said the new technology costs a minimal amount, and the engines will be standard on many pickup trucks and sport-utility vehicles.
The V-8 engines will boost fuel economy by up to 25% in certain driving conditions. However, the listed fuel economy will rise by about 8%, based on the testing procedures required by the Environmental Protection Agency, which simulates rush-hour traffic.
