Nissan Sentra wrings out 1 mpg more to sweeten payout

Engineers at Nissan Motor Co. are scurrying to eke another mile or two per gallon out of their vehicles to win customers who come looking for federal cash-for-guzzlers money.

"We want as many of our products as possible to pop up on the shopping list," Nissan North America spokesman Brian Brockman says.

Dealer enthusiasm and ad hype already are making cash-for-guzzlers the auto marketing event of the season. Nissan's actions show how automakers are enlisting engineers and others in their eagerness to take part.

Realistically, there is little Nissan's vehicle engineers can do to improve fuel economy dramatically in the short amount of time the federal program is scheduled to run, concedes Robert Sump, vice president of Nissan Technical Center North America in suburban Detroit. The usual ways to cut fuel consumption, such as eliminating engine friction or switching to lighter materials, often take years.

But a number of quick changes are possible, especially if the government decides to extend the program. It is scheduled to run until November, or when the $1 billion runs out.

Engineers in Michigan and Japan are focusing on changes in engine tuning, uses of different wheels and changes in vehicle options.

Retuning the Sentra's four-cylinder engine has added 1 mpg--which could be the difference in creating a 10-mpg difference between the new vehicle and the trade-in, triggering the highest possible credit of $4,500.

"We've tuned several vehicles on the fuel economy side to get you a mile per gallon," Sump said.

Any improvements will have to be reviewed and confirmed by federal regulators with the EPA. But Sump believes even fractional improvements in fuel economy by his team--a gain of 0.6 mpg, for example--might be rolled up into a full additional point on a vehicle's window sticker by EPA regulators.

Nissan, like most automakers, already was looking for fuel economy enhancements before the program emerged. But the expected bubble in 2009 sales created by the lure of trade-in bonuses has prompted Nissan to divert the focus of its engineering staff onto the mission.

"This program is a driver for us for the next few months," Brockman says. "We don't want to miss out on that."

By Hans Greimel and Lindsay Chappell- Automotive News