Dear Tom and Ray:

I have a 1986 Toyota Corolla that keeps on going! My question is about gasoline. I have started to walk the 1 mile to work for health reasons and because gas prices are so darned high. I fill up my tank, oh, about once a month or so. My husband says I should be using gasoline stabilizer to keep the gas fresh in the tank. Is this for real? Does gas really go bad? How long does it take to go bad? Please let me know, because I don't want this to be an excuse for me to stop walking to work. -- Carol

Ray: Well, my brother happens to be the world's foremost authority on bad gas, Carol. Ask anyone who's ever been on a long car ride with him.

Tom: Gasoline DOES go bad, Carol. And there are two things that happen to it. One is that the volatile portions of the gasoline evaporate over time. And that makes your car harder to start, since the engine counts on being able to vaporize the gasoline in order to ignite it.

Ray: The other thing that happens is that "gums" settle out of the gasoline. And these syrupy byproducts can gum up your gas filter (if you're lucky), or your fuel injector nozzles or carburetor passages (if you're less lucky).

Tom: But the good news is that, according to Lew Gibbs of the Society of Automotive Engineers, gas really isn't in danger of going "bad" for about a year. Gas can even be fine for more than a year. But a year is the point at which gas is considered questionable.

Ray: So if you're going to leave your car for a year or more, then you want to add a gasoline stabilizer and fill up the tank all the way to minimize the gasoline's contact with air -- which is what causes the gums to form.

Tom: But if you're filling up the tank once a month, or even once every couple of months, there's absolutely nothing to worry about, Carol. Keep on walking. Good for you.

To buy or not to buy -- options, that is. Are options worth what you pay for them, or are you better off just going with the basics? Order Tom and Ray's pamphlet "Should I Buy, Lease, or Steal My Next Car?" to find out. To order, send (check or money order) to Ruin, P.O. Box 536475, Orlando, FL 32853-6475. You can also order online.

© 2000 by Tom and Ray Magliozzi and Doug Berman Distributed by King Features Syndicate, Inc.

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