Dear Tom and Ray:

I change the oil and filter every three months on my '85 Olds. I usually
have 1,500 or fewer miles on it between changes. Can I wait longer between
changes? I have several cars, and that's why the mileage is low. -- George

RAY: You certainly can wait longer between oil changes, George.

TOM: Any recommended oil-change interval is just an estimate anyway. The
idea is to change the oil before it loses its ability to properly lubricate
the engine and hold contaminants in suspension. And most car manufacturers
think oil can perform those duties for at least 7,500 miles.

RAY: We happen to recommend an oil and filter change every 5,000 miles (or
about every six months). So with the small amount of driving you do, I see
no reason why you can't go six months between oil changes.

TOM: That's from a purely automotive point of view, of course. If, on the
other hand, doing that oil change is keeping you out of trouble, George,
and the alternative is to spend Saturday at the track losing 100 bucks,
then you might want to leave well enough alone. But you'll have to factor
in all the "holistic" variables yourself.


For Monday:

The Feds chime in with the low down on high octane, in today's Car Talk column.

Dear Tom and Ray:

We at the Federal Trade Commission would like you guys to help spread the
word about buying -- and not overbuying -- the proper octane gasoline. For
years, gasoline companies have been pitching higher-octane gasoline as a
way to lower maintenance costs. We recently reached a settlement with Exxon
which mandates them to run ads explaining the proper selection of octane,
which is -- as you guys say -- based on the recommendation in your owner's
manual. To further emphasize this message, we have produced a new, free FTC
brochure "The Low-Down on High Octane Gasoline." Please tell your readers
that it's available. -- Don Elder, Bureau of Consumer Protection, Federal
Trade Commission

TOM: Geez, Don. Don't scare us like that, will ya? When we saw a letter
come in from the Bureau of Consumer Protection, we immediately assumed that
you were coming after us for our "5/50 warranty."

RAY: That's five minutes or 50 feet from the garage, whichever comes first.

TOM: Actually, we'll be glad to repeat the message. High-octane gasoline is
of absolutely no benefit to the vast majority of cars on the road. You
should only use high-octane fuel if your owner's manual specifically
recommends it.

RAY: Or if your car knocks or pings on your normal grade of gasoline, and
your mechanic has been unable to find any other easily fixable cause.

TOM: If you want more information, you can get the free FTC pamphlet on
octane by writing to:

Federal Trade Commission
Consumer Response Center
6th St. & Pennsylvania Ave., NW
Washington DC 20580.

RAY: Or call them at (202) 326-2222, or visit their Web site
at http://www.ftc.gov.