Washing a car below freezing

The paint is not the problem

A lot of people skip washing in January because they think the cold will damage the paint. It won't. Clear coat handles cold water fine, and leaving salt on it for weeks does far more harm than any wash. The real issue below zero is the water that stays behind in the gaps: door seals, lock cylinders, handle mechanisms, the wiper arms, the fuel door and the window channels.

There is one thing worth checking first. If the windshield has a chip or a small crack, big temperature swings can make it spread, and a winter wash followed by a blasting defroster is exactly that kind of swing. Getting chips repaired before winter is cheap insurance.

What to do in the first few minutes

Most of the trouble can be avoided by spending three or four minutes with a towel before you drive away. Pull into a parking spot rather than stopping in the lane out of the bay, and keep a dry towel in the car for this.

• Open each door and wipe the rubber seals and the bottom edge of the door
• Open and close every door, the trunk and the fuel door a couple of times to break any ice film
• Lift the wipers and wipe the blades, then run them once
• Run the windows down an inch and back up so they don't freeze to the seals
• Turn on the heat and defrost before you leave

The parking brake and other surprises

On some cars, especially older ones with a cable parking brake, setting the brake while everything is wet in deep cold can freeze it on. If your car has a cable brake and you're parking outside right after a wash, it can be safer to leave it in park on level ground and skip the brake until things dry. Cars with an electronic parking brake behave differently, so check the owner's manual for winter advice.

Driving for ten or fifteen minutes after the wash helps a lot. The heat from the cabin and the airflow at speed dry out the door edges and mirrors. Washing on the way home and then parking outside overnight is the worst order to do things in.

Picking a better day

A sunny afternoon a few degrees below zero is a much easier day to wash than a windy evening at minus fifteen. The sun warms dark panels, the water drains before it freezes, and you have daylight to check the car. If you can, wash in the early afternoon and drive somewhere afterwards.

When there's a long cold snap, don't wait it out. Two or three weeks of salt sitting in the seams is worse than a wash on a cold day, as long as you dry the openings afterwards. Fast Lane is open 24 hours, so it's easy to go at midday on the warmest day of the week.