Q: What happens if you put 5 gallons of diesel fuel in a gasoline engine's fuel tank, but you don't try to start the vehicle? -- Anthony

A: Let me guess, Anthony. Asking for a friend?

If you haven't tried to start the car, you haven't done any serious damage yet. Once you start the car, the fuel pump sends that diesel fuel into the fuel lines and through the injectors. And that makes a pretty good mess. But if all the diesel fuel is still in the tank, this is not going to require a home equity loan to fix.

The first step is to have the car towed to your mechanic. Obviously, you don't want to drive it to him. He'll drain your gas tank. Some cars actually have removable drains on their gas tanks. If yours is one of those, you're in fat city. He'll just open the drain over an approved container and let the entire contents of the fuel tank come out. Then close it up, add some fresh gasoline, and drain that mixture to get out most of the remaining diesel. He might even rinse it with fresh gas more than once.

If there's no drain on your gas tank, your mechanic will have to remove the gas tank and empty it for you. We call that "dropping the tank," even though we don't actually drop it. Well, once in a while we drop it. Anyway, once he dumps out the existing fuel, your mechanic will do the same thing with some fresh gasoline, swishing it around in there to help remove whatever diesel remains. That should get rid of 99.98% of that diesel fuel.

Once you've drained and cleaned the fuel tank, there's nothing else you really need to do. Since you never started the car, don't get talked into replacing any fuel lines, filters, converters, seals or injectors. It won't be necessary.

Even if you have a little bit of diesel residue in the tank -- the stuff that's still clinging to the walls -- when mixed with enough gasoline, it should just get burned up in the cylinders and go out the tailpipe. By residue, I mean ounces, not pints or gallons.

I'd warn you to be careful to not do this again, but I'm sure that after you have to spend a couple of hundred bucks removing the tank, you won't need any further reminders. Good luck, Anthony.

Q: Is it OK to raise up my windshield wipers in the winter? I see people doing that sometimes, to prevent the wipers from freezing to the windshield. Will it weaken the springs over time? -- Fred

A: This is a trick that people use in the Great Frozen North, Fred.

When there's a snow, sleet or ice storm coming, some people will raise their wiper arms away from the windshield the night before. That way, if the windshield ices up, the blades will be out of the way, making it easier to get to the windshield with your pick axe the next morning. It also saves you the trouble of having to separate the iced-over wiper blades from the frozen windshield.

I suppose it's one of those small pleasures we Northerners take. "Hey, I may have to dig my car out of 4 feet of wet snow and chip ice off my windshield an eighth of a centimeter at a time until I can't feel my fingers, but at least I don't have to clean my windshield wipers!"

Most people do this a handful of times per winter. And that's not going to harm the springs, which are pretty robust. If you're doing this every night, Fred, then forget about your wiper springs, relocate to Honolulu.

Those springs are responsible for keeping the wipers pushed up against the windshield, so they're being worked all the time anyway. And if, for some reason, the springs on your wiper arms do weaken over time, and you get chattering or poor wiper to windshield contact, you can always replace the arms. On the average car, replacements will cost you 25 or 30 bucks a piece. So it's not a big deal.

There are also other ways to reduce the amount of work you have to do on snowy mornings. There's the heated garage, of course. But if you don't have one of those, you can put a tarp over the windshield, and just pull it (and the snow covering it) off before you drive away. Or get one big enough to cover the roof and hang down over all your windows.

In fact, that'd make it nice and dark in the car, so you might want to consider sleeping in there, too.

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Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.