Which detergents to use washing a car

Dishwashing detergent may make plates and bowls sparkle, but it's murder on a car’s finish.

The very properties that allow it to cut through dirt and grime, as demonstrated nightly on TV, also do a good job of stripping away a vehicle’s protective wax – the opposite of what you’re trying to achieve.

For the same reason, all household cleansers should remain in the house... not applied to the sensitive paintwork of your car. So that's all your abrasives for porcelain and tiles as well. Forget about them, you need a detergent that has been specially formulated for automotive finishes.

There is an easy way to find a suitable detergent; just take a trip to your local car accessories store, where you'll find a kaleidoscope of exterior car care products stocking the many shelves.

You’ll also see them in supermarkets, service stations, department stores… all over.

To apply the detergents, wax and polish you’ll find myriad sponges, brushes, gloves and hose nozzles as well. All alongside the pre-wash products, washes, scratch removers, bug and tar removers, glass cleaners, waxes, polishes, tyre blackeners, wheel cleaners, chrome polish, alloy wheel polish, rain repellent and more.

All have a place in the quest for the sparkling car with its paintwork under constant attack.

Nasties such as tar, UV rays, salt, grit, rain, snow and mud, soot, bird droppings, cold, heat, industrial fallout, tree sap and pollen are on the attack the minute the car is driven from the dealer’s lot or from your driveway.

Experts recommend a wax coat when the finish no longer “beads” water. Most polishes will last from six to 12 months.

It sometimes helps to use a rubbing or polishing compound. These provide oxidation to remove minor scratches and scrapes. Rubbing compounds revitalise dull finishes; polishing is for faded surfaces.

However, they need to be used with care: read the instructions carefully or you might mar the surface.

Separate products are available for wheel cleaning. Their job is to polish and protect without scratching, while restoring shine, removing surface muck and some scratches.

Still other cleaners look after the tyres. Silicone-based cleaners penetrate the rubber providing long-term protection, compared to water-based cleaners that dissipate in the rain.

However, some silicone products leave an “oily” appearance that you may or may not like.

Cleaning solutions, where to get them and how to use them

After a wash and dry, lightly run the palm of your hand and fingers over the bonnet and roof.
If the paint doesn’t feel as smooth as glass, it needs waxing.

Do the job when it’s cool and shady, not in the heat of bright summer sun.

Apply polishes and waxes with a foam applicator and wipe off with terry towelling cloth.
Most other types of applicators, including cheesecloth, may leave fine scratches.

Always quickly remove airborne contaminants like dust and grime, tree sap mist, bird droppings and salt air; they may bond or etch into the finish.

A newly painted car should be given time to properly cure. Wait one or two months before using wax or polymer sealant.

Related: How to wash your car
Related: How to polish and buff out scratches on a car
Related: How to keep your car's paint pristine this summer
Related: How do I remove bird poo from my car?
Related: Washing the car at home

This article was originally published in 2007, but has been recently updated
Pictures courtesy of Karolina Grabowska from Pexels