Regardless whether you’re working on your racecar, street car, family car or tow vehicle, the wheels will get dirty. If you wash a car, and the wheels are dirty, the whole car looks dirty, but given the variety of metals and finishes used for wheels — and nearby components — there is a science to the process of cleaning wheels. Choosing and using the right chemicals and materials can help you get the best results.
“Wheel cleaning is probably one of our industry’s kind of a sore thumb. So this is like the perfect topic,” said Mike Pennington, Meguiar’s director of global training, event marketing and consumer relations. “No matter how much people think they know, it’s quite interesting. We get many calls, you know, they might be using the right product, but they choose the wrong one. So choosing and using is like the perfect one, two punch.”
The great thing about wheel cleaners is that no matter which brand you prefer, all the rules for choosing and using wheel cleaners apply universally. The guidelines are brand agnostic, so to speak. When people ask what the best wheel cleaner is, you have to back up and understand the surfaces you working with. Wheels are made from different metals and have different finishes, and the wrong wheel cleaner, regardless of brand can be as harmful as it is good at cleaning.
It also extends beyond the materials and finishes used on the wheels. When you spray a wheel cleaner, it affects rotors, the brake calipers. Two-piece rotors with anodized hats that are more delicate than the friction surface. There’s also suspension components that could be affected. The most delicate of the materials dictates what wheel cleaner you should use.
Wheel and Tire Cleaner
“Part two of that is when you actually pick that wheel cleaner, obviously there’s some challenges. You know, pH, 7 is essentially neutral down to 1 is acidic, up to 14 is alkaline. Obviously you, you’ve got bleach on the alkaline side, all the way down to, you know, batteries, lemons, things like that on the acid side. All these different wheel cleaners have different pH’s, and a good rule of thumb is, believe it or not, the further away you go from neutral, it’s dangerous in both directions. The further away you go from 7, the stronger they get. But the more dangerous they get, obviously, right?
A cleaner designated for aluminum wheels typically falls in the neutral range, so it’s the safest bet. Conversely, chrome wheel cleaners are more acidic, typically measure from 3 to 5, so they’re more acidic. Wheel and tire cleaners, they’re up in the 12-plus range, more alkaline. Use the wrong cleaner on your wheels, they could cause etching and discoloration, so it’s important to understand what you’re working on. The safest wheel cleaner has a pH of 7, but it might not be as strong as needed for a chrome wheel caked in brake dust. An all-purpose cleaner would be neutral, too.
All Purpose Cleaner
Because wheel cleaners don’t magically dissolve grit and grime into thin air, a set of wheel brushes is also a good idea. Brushes with long handles can get in the inner barrel if you want get that finicky. There are also specific brushes for lug nuts, for the wheel face and different materials, from plastic bristles to wheel woolies. You can go as crazy as you want. A pressure washer is also going to be beneficial, especially for race wheels that have heat-soaked in brake dust.
So, three key elements in achieving the desired outcome are the right wheel cleaner, brushes and a pressure washer.
That brings us to application. Naturally, just as you wouldn’t wash and wax a car in the hot sun, wheel cleaning is best done when they’re cool to the touch. Pennington pointed out that that spraying wheel cleaner on a hot wheel makes the cleaner more aggressive. So what started out as the right choice now has the potential to discolor and stain and be destructive.
Aluminum Wheel Cleaner
Believe it or not, how you spray the cleaner on the wheel also is important. After rinsing off as much brake dust as possible, spraying from the bottom up is the best way to achieve uniform coverage. Spraying from the top down can lead to runs and uneven cleaning. Because wheel cleaners are different, it’s important to read the directions.
“A lot of wheel cleaners will say dwell. Some say don’t let it sit longer than X amount of time,” Pennington said. “But really, following directions, grabbing that appropriate wheel brush, for your inner barrels first, then your lug nuts, then you wheel face, you might even have a separate brush and clean your wheel wells at that time. Then take your high pressure and rinse thoroughly. Again, we can’t stress that enough — rinse thoroughly and do one wheel at a time.”
Doing one wheel at a time minimizes mishaps if you do something wrong.
When it’s time to dry the wheels, you can use compressed air or a leaf blower, or any kind of towel. Just be sure you don’t use that towel for anything but wheels. For race wheels, you might not even dry them at all. If it’s a hot rod or a show car, you probably want to dry them well so there is no spotting.
“When you walk into Auto Zone, the ‘wheel and tire cleaners,’ those are the ones that are higher pH. Those are really for factory, the silver wheels you find on most new cars, you know, they’re just old school, silver wheels painted, coated. That’s what those are designed for,” Pennington said. “And then there’s also the last big category that you find on the shelf is what’s called all wheel cleaners. And those are, those are similar to let’s say an aluminum wheel cleaner that they’re very safe, but they have a little bit more bite to them than a traditional aluminum wheel cleaner. So aluminum wheel cleaners are probably the safest and least effective. But it’s obviously not going to be as strong as a chrome wheel cleaner because a chrome wheel cleaner is going to be much more acidic.”
Cleaning Race Wheels
To reiterate, the most delicate surface you’re treating dictates what cleaner to use. Say you have chrome wheels with chromed plastic center caps. Pennington recommends choosing the milder cleaner and taking other steps to ensure good results.
“So if you’re, if you’re concerned and you’re really, let’s call it OCD is a good word. I’m going to use that very positively right now. Then you’re still going to want to back down on the chemical, grab a proper wheel brush that’s soft,” he said. “So you let your mechanical and you let your water pressure be your best friend. You don’t rely so much on the chemical aspect of it.”
Filthy Race Wheels
Here’s where we go off script a bit to discuss drastic measures, and we didn’t ask Pennington about this one because we’re certain he would be mortified. Say you have aluminum wheels with no clear coat on them, and they have been neglected their whole lives. Think of the factory aluminum five-spoke wheels that came on the 1999 and 2000 Mazda Miata. If those wheels haven’t been cared for, they can become unfathomably ugly, and regular wheel cleaners just don’t cut it. That’s when you go for the nuclear option: oven cleaner.
Use the same method of spraying from the bottom up to get uniform application. How long you leave it on is up to you, but you can usually see how well it’s working. Oven cleaner can’t be good for tires, but this is the method of last resort, and it does work when conventional chemicals fall short.
“The good news is all these wheel cleaners that you find on that shelf will boldly call out ‘chrome wheel cleaner,’ ‘wheel and tire,’ ‘aluminum,’ ‘all wheel.’ Those are somewhat uniform for all manufacturers,” Pennington said. “The disconnect is people don’t typically know what kind of wheel, brakes or surface they’re working on before they walk into the store. So, I think the golden rule is if you do not know what kind of wheels you have and you want to take the safe route, we would highly recommend going with an all-wheel cleaner because they’re going to be safe on everything. And an aluminum wheel cleaner would also work. But don’t risk going with anything else.”
Especially not oven cleaner.