Q My car was caught in a sandstorm. There was no damage except for windshield pitting caused by the sand. It isn’t noticeable until I drive into the sun—then it’s difficult to see through the suddenly cloudy glass. How can I get those pits out of the windshield without replacing it?
San Rafael, California
A It’s very unlikely you can buff out a windshield’s worth of pitting and emerge with a perfectly clear piece of glass that is safe to use. Replacement is the best course. Buffing can help, and nearly cure, small blemishes, but can create a bit of haze itself. The common kind of windshield damage, small pits and minor cracks caused by flying pebbles, generally can be fixed and made reasonably invisible by injecting sealant into the fissures. Our Sacramento Car Care Plus facility has cured many such dings this way, but has never revived a sandblasted windshield.
Q My car is supposed to use premium gas. I have tried running it with regular, and there doesn’t seem to be any difference in the way the car behaves. Is it really necessary to use premium gas, and will using regular damage the engine?
J. DANIELL HEBERT
San Francisco, California
A With reservations, yes to both questions. Computer-controlled fuel injection meters fuel far more precisely than even the most talented carburetor might hope to and can compensate a bit for some gasoline’s tendency to burn before it should in the cylinder. In a pinch, a tank of regular will probably do no permanent harm, especially if you drive with a light foot. But since your car evidently has a high-compression engine, it’s best to stick to the manufacturer’s recommendation for octane rating. Using regular in such an engine is likely to result in premature burning (which causes the pinging you can hear—and the extra heat and stress your engine can feel). High-octane fuel resists this. The reverse situation, using premium gas in a car designed for regular, causes no damage, except to your wallet: The great majority of cars are meant to use regular, and would run no better or worse (just more expensively) if given premium.
This article was first published in January 2006. Some facts may have aged gracelessly. Please call ahead to verify information.