There are some paint safe touch-less automatic washes out there. We don't want to lump all of them into a negative category.
Protect your investment! Don't destroy it. So you just bought a brand new car, and the last thing you want is to ruin that shiny showroom finish. As the miles pile on and it starts to show, your first instinct might be to rush to an automatic car wash. After all, convenience is the new king, and what could be easier than driving in dirty and driving out sparkly clean, all while being splattered by multi-colored rainbow soap? As a proud car owner, that sounds like a no-brainer, right?
Think again. Automatic car washes can be convenient, but the costs in potential damage add up quick. They have been known to often introduce swirls, scratches, and other marring to your car’s paint. Taking a nice car to a mechanized or "full-service" car wash is like going to the best steakhouse in town and ordering your prime rib well done. It's a waste of money, and for bona fide car guys, it can be painful to watch because it's actually pretty bad for your car. Keeping that in mind, here are several reasons why you benefit by avoiding automatic car washes:
You're literally spraying your car with acid. Actual acid!
This isn't a metaphor, nor am I making some ecological point about acid rainwater. Hydrofluoric acid can be a mean SOB -- you might remember it from Breaking Bad, wherein it was used to dissolve bodies.
Well, it's particularly well suited to eat away very fine particles... like road grime. As a result, a lot of those "pre-cleaners," "heavy-duty cleaners," and most wheel cleaners have hydrofluoric acid in concentrations strong enough that the CDC even issued a warning to all car wash industry workers.
Automatic car washes are designed for speed and convenience, not attention to detail. You may trust that the operator is using appropriate soap in the right amount, but are they? Chances are, they are using a cheaper product to increase their profit margin. These chemicals are usually a strong acid that also strips off any protective coating applied to your car such as a wax or sealant.
You're putting about a billion tiny scratches in your paint
OK, even if you forget about the acid for a second, you're still hurting your paint every time you go to an automatic carwash. Remember those horrific giant spinning monsters from decades past that would maul your car to get the dirt off? Those are mostly extinct today, but even the "softer" brushes repeatedly slap against your car and drag across its paint, carrying with them a bunch of dirt, not just from your car, but from the car in front of you, and the one in front of it, etc. Each particle is essentially a tiny piece of sandpaper eating away at your car's paint.
Unless the brushes are meticulously cleaned between washes, that same dirt is being kicked up and dragged across your car’s finish.
Even water pressure can cause damage
For the sake of argument, pretend you have a small rock chip. Maybe it's brand new and you've never even seen it. A quick blast of water at close range with enough pressure is all it takes to do serious damage. If your paint happens to get pressurized water under it, it can force up the exposed edge and peel away even more paint. Most car washes also filter and recycle their water to cut down on the sewer bills, thereby lowering the automatic car wash owner’s overhead. Recycling the water means that any dirt and grit missed by the filtering system will affect how much dirt is being sandblasted back onto your car during the wash and rinse cycles.
Water spots are terrible for your car
Unless you're using water that's so heavily filtered it can be used in a medical saline solution, it can leave mineral deposits on your paint if it evaporates too quickly. Not only are water spots ugly as sin, they're basically permanent -- like cleaning soap scum off your shower, you can't always get them off without heavy-duty polishing. If you run through the car wash and get back on the road without drying, or by simply letting those cool-but-worthless giant hair blowers push the water around, you will cause damage to your paint once you're back out in the hot sun.
Questionable Drying Methods
Take a look at the rags being used. Pay attention to how many times those rags get dropped on the ground and picked back up. Now go drop a damp shirt outside and see how much grit it picks up. Still want it rubbing against your body? Neither does your car. Hand drying your car is the most effective only if fresh, quality microfiber towels are being used, which is often not the case. Using a microfiber towel is crucial to not creating tiny swirls and scratches in your car’s paint. They are highly effective at absorbing water, too, much more so than a regular towel.