General Motors will boost the fuel economy of its 2005 full-size pickup trucks and sport/utility vehicles by an average of one mile per gallon through improvements in technology and design, according to the Detroit News
on July 1. The automaker claims the improvements will save about 28 million gallons of gasoline a year, based on annual U.S. sales of 1.3 million vehicles that travel an average of 15,000 miles a year. To raise fuel economy, GM is making four improvements: Mechanical cooling fans are being replaced with electric fans that turn on only when they are needed — resulting in about one-fifth of a mile per gallon improvement.
Axle ratios have been lowered to improve gas mileage by about one-tenth of a mile per gallon. The lower the axle ratio, the fewer times the drive shaft has to turn to spin the wheels.
Several aerodynamic changes — sealing tow hook holes when tow hooks are not installed, recessing rear high-mounted brake lights, improved running boards, extending front air deflectors and sealing fog lamp openings when the lamp is not installed.
A regulated voltage control that monitors the remaining charge in the battery will also be installed. “It controls the generator output so we don’t suck more energy out of the engine driving the alternator than is needed to charge the battery,” said Bob Kruse, executive director of vehicle integration for GM.
All four changes will improve fuel economy by three-quarters of a mile per gallon, and Kruse said an additional quarter of a mile savings will be realized once the changes are developed, refined and validated. The changes will not result in any additional cost to consumers. The fuel economy of GM’s full-size pickups and SUVs ranges from 10 miles per gallon in the city and 21 miles per gallon on the highways, according to EPA figures.