Q: I purchased a new Corvette in 2000. My odometer reads 40,576 miles. I have been very diligent to have a once-a-year oil and filter change, engine and cabin air filters, if needed, and fluid flushes such as engine coolant, power steering fluid, brake fluid, etc. How often should I be having the various flushes and fluid replacements done? I only drive the Corvette from late March to late November of each year. — D.P., Naperville, Ill.
A: Your car needs an annual oil change and a coolant change based on the schedule in your owner's manual. It does not need routine flushes for other fluids. In February 2013, the California Bureau of Auto Repair (BAR) released a consumer brochure warning consumers of the practice of selling unnecessary or dangerous services to unwitting car owners, known in the industry as a "wallet flush." The bureau has no problem with add-on services as long as the need is proven, and that the servicing facility gets a full background of how you use your vehicle and that you fully understand that it may not be a factory-recommended service.
Q: I haven't seen many, if any, car bras nowadays. I was wondering if they actually helped keep road chips from damaging the hood and front bumper. — T.Q., Bluemont, Va.
A: We never quite understood the fascination with bras. It was always our opinion that they trapped moisture and road grit and grime. That would really mess up the paint. Bras gave way to helicopter tape — strong plastic used to prevent sand damage to the leading edges of helicopter blades developed during the Vietnam War. A similar film was developed for cars, but usually has to be installed by a professional. This year, 3M announced a do-it-yourself product sprayed on from an aerosol can. The Paint Defender dries to a flexible plastic film that the company claims lasts a year or more and can be peeled off.
Q: My 2004 Chevy Impala has three inches of water contained in the light panel that goes across the trunk. Obviously there is seepage somewhere which that caused the rain to come into the space. The car is nine years old and I was told the dealer is not responsible after five years. Is there any other possible way to fix this? — B.P., Chicago
A: We are not clear on where the problem is, but we are sure that a body shop would know how to deal with it. Water intrusion happens, but we have not heard that it is common in, what we suspect, is the taillight assembly. There are ways to fix just about anything.
Q: When the car manual for my 2007 Toyota Camry indicates 4.5 quarts and I have half a quart left, can I put the remainder in without causing any damage? Is using a lesser-known brand OK? Is 5W-20 all I need to know in comparing motor oils? Is synthetic oil and "fully" synthetic the same? — J.G., Canton, Conn.
A: It is not a good idea to overfill your engine's crankcase. Just put the lid on the bottle and toss it in the trunk to top off the oil as the level drops. Not all motor oils are the same, and the SAE viscosity numbers (e.g., 5W-20) don't indicate whether the oil is right for your car. Instead, make sure the oil meets the API and/or ILSAC specification found in your owner's manual. Unless the label states that it is a synthetic blend, the oil inside is fully synthetic.
Q: My 2011 Equinox manual says to use only oil with the dexos certification mark on the label and that "failure to use recommended oil can result in engine damage not covered by vehicle warranty." The next paragraph says if dexos not available, you may substitute oil displaying API Starburst symbol and SAE 5W-30 weight. Can I use conventional motor oil without fear of damage? Does the car recognize synthetics? — B.B., Addison, Ill.
A: GM strongly suggests you use oil meeting its dexos® standard as the oils are designed to offer higher engine temperature protection, better fuel economy, better sludge and emissions control and be more compatible with alcohol-laced fuels, according to GM. Some oil companies' products meet the dexos specifications, yet they refuse to pay a royalty to GM to use the trademark. Your engine has no way of determining what is in it and neither does the dealer unless he sends a sample out for analysis.
Q: I have a 2012 Kia Soul and I add 2 ounces of acetone at every fill-up. I heard that it increases your gas mileage. To your knowledge, is it true, and, could it hurt anything in the engine? — J.C., Allentown, Pa.
A: Acetone does not help the fuel burn better or increase fuel economy. In the amounts usually suggested (approximately one-quarter of 1 percent by volume), we doubt that acetone would have much effect and, if it did, additive-makers would be selling it to gasoline companies. Acetone is an excellent solvent and was widely used in fingernail polish remover. It readily dissolves polycarbonate plastics such as those used on in-line translucent fuel filters. It will also attack nitrile rubbers such as those used for fuel lines. Dissolved rubber can clog fuel injectors and the pickup filter in the gas tank. The dissolved rubber may also coat the fuel pump armature and the activated charcoal in the onboard emissions vapor control device. Additionally, weakened fuel hoses may rupture creating a fire hazard. At $25 per gallon, don't waste your money.