DETROIT — In a normal year, the 2009 Chevrolet Cobalt wouldn’t be any different than the 2008 model, save for a few minor cosmetic changes. But this is far from a normal year.
With gasoline still hovering around $4 per gallon, many manufacturers are making far more than the usual tweaks to cars and trucks between model years to squeeze out 1 or 2 more miles per gallon and catch customers who increasingly rank fuel economy as a top factor when buying a vehicle.
Automakers say you can expect more of the same as they roll out new technology without waiting for full vehicle updates.
“Fuel economy is very important,” said Greg Peterson, General Motors’ vehicle-performance manager for compact cars, including the Cobalt. “That is one of the drivers in the changes that we made.”
In the high-mileage version of the Cobalt and its Pontiac sister, the G5, engineers varied the intake and exhaust-valve timing to make the 2.2-liter four-cylinder engine burn fuel more efficiently. They arranged with Goodyear Tire & Rubber Co. for tires with lower rolling resistance, and they changed the gear ratios of the five-speed manual transmission so the engine revs more slowly on the highway.
The result: an extra mile per gallon on the highway, boosting the Cobalt and G5 XFE models to an Environmental Protection Agency estimated 37 mpg.
