Can Maintaining My Car Save Gas?

Q. With gas prices so high, is there anything I can do to my car to improve its fuel efficiency and cut my fuel costs?

A. You can improve your gas mileage by making some low-cost, easy changes in maintenance. But keep in mind that the amount of gas _ and money _ you save will be incremental. Still, every little bit helps.

It's no secret that trading in your vehicle for a more efficient one, or changing your driving habits can cut your gas bills. But while those choices can be costly or require significant adjustments, the changes in auto maintenance require little more than added mindfulness.

''In many cases, there are other reasons to do these things, in terms of safety, in terms of cost savings, in terms of preserving your car and so forth,'' said Therese Langer, transportation program director at the American Council for an Energy Efficient Economy, a Washington-based think tank.

The average U.S. household will spend more than $3,000 this year on gasoline _ a figure based on the optimistic assumption that the price per gallon will average about $2.50, according to the Alliance to Save Energy.

''That's utopian,'' said Ronnie Kweller, a spokeswoman for the group.

But making a few changes in auto maintenance can cumulatively save 10 percent or more. In a household spending about $250 a month, that's a $25 savings.

So what should you do?

For starters, make sure your tires are inflated to the correct pressure, experts say. The Environmental Protection Agency estimates doing so can improve gas mileage by 3 percent.

''If your tires are underinflated, it's like driving around with a parking brake on,'' said Rich White, a spokesman for the Car Care Council, funded by an industry group of companies that manufacturer and sell vehicle parts and supplies.

It also can help to get your wheels aligned and balanced. Some tire manufacturers also now sell tires designed with lower rolling resistance to improve fuel efficiency.

Replacing your car's air filter if it's old and clogged can also make a difference, improving mileage by as much as 10 percent, according to the EPA. Air and fuel filters should be checked twice a year.

Those checks can often be done along with an engine tuneup and oil changes, both of which can improve mileage.

In addition, make sure to use the motor oil recommended by your car's manufacturer. Using the right one can improve fuel efficiency by up to 2 percent. That's particularly true if you use oils labeled as ''Energy Conserving,'' which will be noted in the round American Petroleum Institute symbol on the container.

What not to do? Experts say that, unless your car's manufacturer has recommended otherwise, spending the money for higher octane gas will not improve your mileage, although it can reduce engine knocking. They also say money is wasted buying fuel additives and add-on devices advertised as improving mileage or emissions.

''Over the years we have done some tests on those products and by and large they don't do what they are advertised as doing,'' said Don Zinger, chief of staff for the EPA's Office of Air and Radiation.