Do's and don'ts of washing your car

For many vehicle owners, the weekend act of washing a car by hand is a therapeutic act as beneficial for the person's state of mind as to the vehicle's appearance. That's good, because frequent washing is also the best way to maintain a new-car finish. But as simple as washing your car may seem, there are some things to watch for so that you don't accidentally scratch or degrade the finish. Here are some basic car-washing tips.

Don't... wait for a layer of crud to accumulate before washing. Dead bugs, bird droppings, and chemicals from the atmosphere all leach acids that can strip away wax and eventually eat into your car's paint. If left too long, they can cause damage that requires sanding and repainting the area to correct.

Do... wash off dead bugs, bird droppings, and tree-sap mist as soon as possible. Other than this, a weekly car wash will keep the finish in its best shape. In addition, if you live in an area that suffers from acid rain, rinse your vehicle off after a period of rainy weather. Otherwise, acidic chemicals in the rainwater will be left on the surface after the droplets have evaporated, leaving a mark that can permanently mar the paint.

Don't... use household cleaning agents like hand soap, dishwashing detergent, or glass cleaner on the paint. These aren't formulated for use on a car's paint and may strip off the protective wax.

Do... use a dedicated car-wash product, which is milder and specifically designed for use on automotive paint. Apply the suds with a large, soft natural sponge or a lamb's-wool mitt. See our car wax report for tips and advice on all types of waxes.

Grease, rubber, and road-tar deposits picked up from the road often accumulate around the wheel wells and along the lower edge of the body. These can be stubborn to remove and may require a stronger product, such as a bug-and-tar remover. Use a soft, nonabrasive cloth to remove these deposits, as they can quickly blacken your sponge.

Use a separate sponge to clean the wheels and tires, which may be coated with sand, brake dust, and other debris that could mar the car's finish. Mild soap and water may work here; if not, a dedicated wheel cleaner may be required. Be sure the cleaner is compatible with the type of finish (paint, clear-coat, chrome, etc.) used on the wheels. A strong formula intended for mag wheels, for instance, can damage the clear coat that's used on the wheels that come on today's cars. To be on the safe side, choose a cleaner that's labeled as safe for use on all wheels.

Don't... wash your car when the body is hot, such as immediately after driving it or after it has been parked in direct sunlight for awhile. Heat speeds the drying of soap and water, making washing more difficult and increasing the chances that spots or deposits will form.