How to wash a car: our top car cleaning tips

How long has it been since you last washed your car? Weeks? Months? It can be tricky to keep it looking its best year-round, particularly if you cover lots of miles, or use your car every day.

Even if you’re determined to maintain a factory-fresh shine, it’s often hard to find the time to wash the car yourself at home. Plus, with thousands of car-cleaning products to choose from, and a wealth of sometimes conflicting advice to be found, it can be all too tempting to put down the bucket and just visit your local car wash.

So, to illustrate that DIY car cleaning can be rewarding, and help you clean your car quickly and effectively, we’ve spoken with expert detailer Richard Tipper, owner of Perfection Detailing.

When should you wash your car?

How often should you wash a car?

From an aesthetic standpoint, it’s really up to you. Cars that cover lots of miles tend to accrue dirt fairly quickly, but a decent wash every few weeks should help keep yours looking presentable – especially if it’s protected with a water-repellent wax or coating.

It’s advisable to clean your car more frequently in winter, particularly the underside, because there’s a lot more dirt, grit and salt on the roads. As well as looking unsightly, this can accelerate the proliferation of rust on the bodywork and essential components.

The best weather to wash a car

Knowing the right weather conditions for washing a car is just as important as knowing how to do it. Although we might not find it the most pleasant weather, an overcast day is best, because it means potentially damaging cleaning chemicals are less likely to be baked onto the paintwork by the sun.

If you don’t have a choice (although, in the UK, a cloudy day is seldom far away), Richard recommends either getting started as early as possible in the morning, or waiting until the evening. Just make sure you don’t wake the neighbours with the sound of your pressure washer at 7am on a Sunday…

If the car is warm to the touch, or if it is a sunny day, bear in mind that you’ll have to rinse chemicals off much more quickly to prevent them drying in place. If it’s particularly bright outside, you might even have to wash, rinse and dry the car section-by-section.

What to use when washing a car

No matter how obscure a mark or stain, you can be fairly sure there’s some potion dedicated to tackling it. However, the vast majority of tasks can be handled by a few basic products:

- Snow foam or all-purpose cleaner
- Alloy wheel cleaner
- Car shampoo
- Glass cleaner

A snow foam and alloy wheel cleaner should be used in the pre-wash stage, while car shampoo should be applied to the car during the main washing stage. Most glass cleaners can be used inside and out, as well as on interior screens and plastics.

Insect removers, iron particle removers, leather cleaners and upholstery cleaners can also be useful for targeting stubborn contamination. For most jobs, pH-neutral cleaners tend to be best because they pose the least risk to paint, metal, plastic and rubber components.

A traffic film remover can be more effective than an all-purpose cleaner at removing serious grime from the underside of a car, but these can be caustic so you should take extra care when using them.

If you are using anything acidic, alkaline, caustic or solvent-based, rinse it off thoroughly to avoid long-term damage to your car’s components or paintwork. And, whatever product you use, be sure to follow the manufacturer’s safety recommendations.

Of course, you’ll need some tools to help you apply and remove these chemicals. Here are the ones we’d recommend:

- Pressure washer
- Microfibre cloths
- Microfibre or lambswool wash mitt(s)
- Wheel brushes
- Drying towel or blow dryer
- Vacuum cleaner

If you’re struggling to decide which brand or product to go for, take a look at What Car?’s product tests. We’ve reviewed everything from car covers to scratch removers, helping you wade through the seemingly endless sea of car-cleaning products to find the ones that offer the best results.

What to wear when cleaning a car

Richard recommends avoiding clothes that could damage the car – exposed buttons, zips, belt buckles and toggles could all cause scratches if you accidentally catch them on the paintwork. With that precaution in mind, wear something that’s comfortable, and that you don’t mind getting wet or dirty.

Pre-wash checks

Dig out all the cleaning chemicals, implements and cloths you’re likely to need before you start cleaning. If you’re using a pressure washer, make sure that it’s working properly, that it’s not leaking excessively and that its filter is clear of debris (you’d be surprised how much gunk can be drawn through a garden hose).

The washing process itself can be split into four main sections:

Car pre-wash

This stage is important because it helps remove grime from the car before you start wiping the paintwork. This reduces the likelihood of scratching the surface with dirt and grit. There are two main components to a pre-wash – wheel cleaning and snow foam. Here's how to get the best results:

How to use snow foam

Using a pressure washer snow-foam lance, apply a snow foam to the whole car, starting at the bottom and working your way up to the top. Leave this to sit for a few minutes (less if the car is warm or in direct sunlight), then use your pressure washer to remove it, this time starting at the top and moving down.

You can get snow foams in a variety of colours and consistencies, but efficacy is much more important than visual wow-factor. Indeed, the all-purpose cleaner Richard uses as a pre-wash doesn’t foam up at all.

How to use wheel cleaner

The best alloy wheel cleaners should help make this often fiddly part of the cleaning process pretty easy. Simply apply, agitate stubborn stains with a dedicated wheel brush then rinse thoroughly with a pressure washer. Most wheel cleaners contain iron particle removers, which help remove embedded brake dust. Many of turn pink when they've done their job, so you can tell when it's time to rinse them off.

It’s important not to aim the pressure washer directly at the brake calipers, however, because this can damage them. Richard recommends spraying water onto an adjacent surface, allowing a more gentle spray to wash over the brakes.

How to wash a car

The main event. You can get car shampoos that you apply using a pressure washer, but a bucket is just as good. Mix car shampoo and water in the recommended ratio, then apply to the car top-to-bottom using a microfibre wash mitt. It’s best to move in straight lines, rather than swirling, and to frequently return to the bucket to rinse off any grime the mitt has accumulated.

Avoid swirling your wash mitt around at the bottom of the bucket; by doing so you risk picking up grit you’ve previously washed off the car. A grit guard, placed at the bottom of the bucket, is particularly helpful here because it stops the grit circulating in the water. If you don’t have a grit guard, it’s worth employing the two-bucket car wash method – in other words, having a second bucket containing just water, for rinsing the mitt each time you take it off the car.

Richard likes to wear a pair of microfibre wash mitts. Not only does this allow you to work more efficiently, but it prevents you from putting a bare hand on the car’s paintwork when leaning across.

Once you’ve cleaned the whole car, use your pressure washer to rinse off all the soapy water.

Finishing and protecting

If that sounds like enough car cleaning for one day (and we wouldn’t blame you), good news: the end is in sight.

Every few washes, it’s a good idea to apply a water-repellent coating to help protect the paint and give it a glossy finish. In the case of Autoglym’s Polar Seal, the process is as simple as applying it with a pressure washer-mounted spray bottle then immediately rinsing off.

Now it’s time to dry the car. A dedicated car blow dryer is the most capable tool, but these can cost hundreds of pounds – a large, clean microfibre car drying towel can do a great job at a fraction of the cost.

The final step is to clean the windows. This is especially important if you’ve applied a wax or water-repellent coating to the whole car, because these can leave a residue that prevents your windscreen wipers from doing their job properly. Clean the inside of the windows first, then the outside, using a dedicated glass cleaner and microfibre cloth. If the cloth starts to leave smears, it may be too contaminated or saturated with cleaner, so it's useful to have a spare cloth to hand.

Car detailing

Of course, if you want to take things further, you can – this is where you stray into the world of detailing and paint correction. You can use a clay bar to remove contaminants from your paint, or scratch removers and car polishes to buff away imperfections and restore your car to its original glory. Here, you're entering the realms of the hardcore enthusiasts and professionals, to the costs and the skills involved can escalate quickly.

Interior cleaning

Start by hoovering the carpets and seats (a car-friendly cordless vacuum cleaner is best); if you’ve got a car blow dryer, you can use this to release hidden dust and dirt beforehand.

A glass cleaner will do the trick for most plastic trims and surfaces, as well as driver’s displays and infotainment screens; simply spray on then buff off for a streak-free finish.

All-purpose cleaners can be used to clean upholstery, but you may find a dedicated upholstery cleaner or leather cleaner easier to use. The best of these just need to be sprayed on, allowed to do their job then wiped off, and some recommend agitating stubborn stains with a brush for the best results.

Try to avoid interior products that contain silicone because this leaves a tacky residue, and is difficult to remove.

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