November 8th, 2022 by Sarah Miles

To keep your car in great condition, it’s not just about the products you use, it’s also about when you do it. Winter conditions mean that car washing is more important than ever but it’s also useful to know when (and when not) to do it.

DO wash when it has been very cold

It is important to wash your car if there have been some freezing temperatures as this means that salt will most likely have been applied to the roads. This is done to prevent ice forming and making the road surface hazardous but when the salt mixes with water and splashes onto cars, this oxidises and becomes corrosive, which will eventually cause rust. This is known as salt corrosion.

You don’t need to worry too much as long as you wash regularly to remove the salt deposits. Regular car shampoo will do the job just fine and one that includes wax will offer some added protection.

However, don’t wash when current temperatures are very cold. This brings us on to our next point.

DON’T wash in freezing conditions

Avoid washing your car when the current temperature is very cold or the car itself is frozen. Most know well enough not to pour hot water on a frozen windscreen to de-ice it and it’s the same principle when washing with warm water.

When very warm water makes contact with very cold glass runs the risk of causing cracking so wait until the ambient temperature and the car temperature are above freezing.

DO wash in periods of bad weather

Obviously, we’re not suggesting that you wash your car in a howling gale or snowstorm but if there has been some bad weather, the chances are your car will be dirtier. Rain, wind, sleet, and snow can all disperse dirt more effectively and it’s also more likely to stick to the surfaces.

As well as looking unsightly, it won’t do your car any favours to leave it sat there for too long. Acid rain can damage surfaces and dirt particles increase the risk of scratching. When there is enough let up in the weather, give it a wash (even if further bad weather is forecast). Ideally, use a non-contact pre-wash like snow foam as this grabs the dirt and allows you to rinse it away before you start wiping anything. Moving dirt particles over the paintwork is one of the greatest culprits for micro-scratches (for this reason, also avoid sponges that can trap dirt in the holes. Microfibre cloths are much kinder to paintwork).
 

DO wash when the car is dry

Further to the last point, you will need to make sure the surface of the car is completely dry if you intend to use snow foam. Snow foam works by clinging to the surface of the car, where it captures the dirt and contaminants. If the surface is wet, it can’t cling and will slide off before it can grab anything.

Wait until the car dries naturally following rainfall, dew, or frost. While you could dry it manually, this may risk scratching, as outlined above, which defeats the point of using snow foam so just be patient.