Are Automatic Car Washes Bad For Your Car’s Paint?

As a kid, one of the highlights of the month for me was going with dad when he would take his work car (a leased vehicle, usually some kind of Subaru – as everybody in New Zealand seems to drive a Subaru) through the automatic car wash at the local petrol station.

The excitement of seeing the big red ‘STOP’ sign light up, and the brushes starting to spin … it takes me right back even to this day.

Happy memories, and all that.

But now I am old, jaded, and have my own cars that I need to worry about maintaining and caring for, I need to think about how I am washing my vehicles.

While automatic car washes are still a very popular option (the queue at the local BP station near me always seems to stretch across the forecourt) you don’t have to dig deep into the world of car detailing to unearth rumours that automatic car washes can damage your car’s paintwork, particularly with repeated use.

Here at Garage Dreams, part of our mission is to help you “preserve” the life and value of your classic (or future classic) car as best as possible. Part of this, of course, is properly looking after the paintwork of your car.

It might be tempting to take a shortcut and clean your classic using the auto wash at your local gas station.

But are automatic car washes actually bad for your car’s paintwork? Let’s look at the truth about auto washes and what they do to your paintwork.

What Is An Automatic Car Wash?

Just so we are all on the same page, I’m referring to one of those “tunnel” wash machines you find a gas/petrol stations, specific wash stores etc.

The sort of thing that looks like this:

Also the sort of thing that the cast of OG Top Gear accidentally destroyed once:

Do Automatic Car Washes Damage Paintwork?

The short answer is yes. And you probably shouldn’t use an auto wash if you want to keep your paintwork in good condition.

The long answer, is yes, and there are a couple of key reasons why these types of washes cause damage.

Even one wash in one of these auto machines can cause swirling and scratch marks on the paintwork of your car.

Every auto wash is different, and every car has a different quality of existing paint finish, so the damage isn’t always as obvious – but basically every time you put your car through an automatic wash you are going to be doing some kind of damage to the paintwork.

At the mild end, this can be clear coat swirling that is primarily visible under light.

At the more extreme end, either a bad wash or repeated use of auto washes can result in more visible and deep scratching:

This is also before you factor in any user error, e.g. going through a machine without your aerial retracted and having that ripped off (although that is perhaps just as likely to result in expensive damage for the carwash owner!)

Also if there is somehow more significant grit or dirt in the brushes of the machine, this can result in more noticeable damage.

Why Do Auto Washes Damage Paintwork?

We’ve established that yes, automatic car washes do in fact damage your car’s paintwork.

But why?

There are two primary factors at play.

The first is that the brushes themselves have an abrasive element. Anything you wash your car with, whether it’s a sponge, a chamois, a wash mitt, or a rapidly revolving auto wash brush, will exert some force and impact on your paintwork, particularly the clear coat.

Imagine if you could move your hand (inside a wash mitt) back and forth over the paint of your car as quickly as an auto wash brush spins – do you think that would cause more, or less, damage than a normal motion?

Secondly, and this is perhaps the bigger issue, the average auto car wash will see dozens of vehicles a day (if not more, depending on how busy the location is). Many of these cars will be quite dirty and covered in grit and grime. For example, here in New Zealand it’s not uncommon to see people head to the auto wash after a busy day on the ski slopes, with their car caked from top to bottom in dirt from the skifield access road.

The brushes in the machine actually pick up this dirt, and because they aren’t cleaned thoroughly enough this dirt and grit is then applied (rather vigorously) back onto the paintwork of your car, which in turn results in scratches and swirl marks – particularly with repeated use.

Another way to think of it is if you were hand washing a car and not properly cleaning off your sponge or mitt between washes – the dirt and grit from the last wash could then be applied back onto the paint at the next wash, causing damage. Add on the more vigorous nature of an automatic wash and it’s not hard to see how the damage can occur.

What About Brushless Auto Washes?

There are some automatic washes that don’t actually touch your car with a brush of any type. These are sometimes referred to as “touchless” washes (although confusingly we have seen some people refer to a touchless wash as being anything where the user doesn’t have to wash their own car).

A genuine brush-free auto wash isn’t going to cause damage in the way that a brushed wash does, because there isn’t the mechanical action of some grit-riddled turbo brush spinning its way across your lovely clear coat.

However, in my experience these touch free washes do a poor job of actually cleaning your paintwork, and probably aren’t worth the money to use. Your mileage may vary, of course.

To compensate for the lack of agitation, these touchless/brushless washes often use a stronger soap formulation. This allows them to achieve a better clean than would otherwise be possible. One thing to note is that this stronger soap might actually strip any wax or sealant that you are using (such as Meguiar’s Ultimate Liquid Wax) meaning that you may need to reapply.

I would still prefer to hand wash my car, but if I had to use an automatic machine it would need to be a no-touch, brushless one.

Conclusion – Are Automatic Car Washes Bad For Your Paintwork?

As a rule, yes they are.

This is because the machines are typically not all that delicate in their operation, but also more importantly that the brushes tend to accumulate dirt and grit that is then thrashed all over your paintwork.

The combination of more vigorous cleaning action from the roller brushes, and embedded grit and grime in the brushes (that aren’t necessarily the softest things to begin with) basically results in a potential paintwork nightmare.

This can result in lots of smaller scratches. In fact, you can often see quite quickly on a car that is frequently being washed using an automatic wash the accumulation of scratches and paint defects. Just the other day I saw an Alfa Romeo 159 that was for sale, which was covered from top to bottom in so many swirls and small scratches that it looked like a different colour to what it was meant to be – this car had clearly spent most of its life going through harsh brush auto washes.

If you’re going to use an automatic wash, then it’s best to look out for a “touchless” one. However, you might find that the final result – in terms of how clean it makes your car – is not great.

Personally, I never use an automatic car wash for my “good” car (my ZC33 Suzuki Swift Sport) – I only wash it by hand. I will admit to occasionally taking my wife’s Subaru Legacy through the auto wash after filling it up, because that car never had the best paint to begin with, and lives a hard life doing big road trips, taking the dog up gravel access roads to the hills for walks and so on.

My preference is still to do a quick hand wash using something like Mother’s California Gold Wash & Wax, which lets me get the car clean to a better-than-machine standard in less time than it typically takes to queue to buy the wash token and then queue again to go through the machine.

If/when we get a new family car, that won’t be going anywhere near an automatic washer, end of story. I do cringe a bit when I see someone with a brand new, expensive car rolling into the local auto wash at the petrol station!

What do you think about using an automatic car wash? Is it something you’re happy to do with your car, or do you prefer to wash by hand? Feel free to leave a comment below, it would be great to hear from you.

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