· by Michael Blair, Nashville's Mobile Detailing
Brake dust is the black film that builds on the face of a wheel between washes, and on some cars it shows within days. The usual answer sold for it is a strong wheel cleaner and a stiff brush. The companies that make the wheels and the cars say close to the opposite, and in much the same terms: a German wheel maker, two Asian carmakers and General Motors all publish nearly the same list of what to keep off a wheel. This post sets that list out, and what it means for wheels through a Middle Tennessee winter.
Why do some cars throw so much brake dust?
On the cars General Motors has written about, it comes from the brake pads they were built with and wheels that show it. GM’s service bulletin 18-NA-067 on excessive brake dust, filed with NHTSA in 2018, calls the dust a normal characteristic: the pad material on high-performance brakes leaves black dust as a by-product, and wheels with large openings between the spokes put it on view. The bulletin covers 2014 to 2018 Buick, Cadillac, Chevrolet and GMC cars and trucks, so it speaks for those vehicles, not for every car on the road.
GM’s remedy in that bulletin is not a stronger product. It is a soft cloth, mild soap and water, a rinse and a dry with a soft towel, with wax afterward if wanted. The dust is expected, and the cleaning is meant to be gentle.
What do wheel and car makers say to keep off a wheel?
Acids, alkalis, abrasives and wire brushes, nearly every time. The wheels Kia and Mazda describe carry a clear protective finish or coating, and that is what the advice protects. Kia’s owner’s manual rules out abrasive cleaners, polishing compounds, solvents and wire brushes, and warns that alkaline or acid detergents can damage and corrode a clear-finished aluminum wheel. Mazda’s CX-3 owner’s manual lists the same tools to avoid and asks you to check a detergent’s ingredients before using it. RIAL, a German alloy wheel maker, rules out cleaners containing acids, alkalis or alcohols, which it says can harm the finish and possibly even the braking system, along with steel wool and scouring sand.
The GM bulletin adds strong soaps and chemicals, acid cleaners, abrasive polishes and abrasive brushes, and says chrome polish does not belong on aluminum wheels. A second GM bulletin, about the Camaro SS’s black anodized brake calipers, warns that acidic wheel cleaners can craze, crack, discolor or remove the caliper finish, that such damage is not covered by the new-car warranty, and that soap, water and a soft brush are usually all calipers need. That one was written about one car, but a cleaner sprayed on a wheel reaches the caliper behind it on any car.
Heat is on the list too. Kia says to clean a wheel once it has cooled, and RIAL says wheels should be cold. A wheel straight off the interstate is not ready.
How often do wheels need cleaning when roads are salted?
More often than in summer. RIAL asks for cleaning at least every two weeks and once a week in winter, outside and inside the wheel. Kia says to clean wheels after driving on salted roads to help prevent corrosion, and Mazda says the same about dusty or salted roads.
That applies here because Nashville’s roads are treated ahead of winter weather. Metro Nashville’s transportation department said in January 2026 that it was pre-treating routes with salt brine and had 100,000 gallons of brine solution and 40,000 gallons of calcium chloride on hand for the 2025-26 season. Our post on road brine and winter car care covers the rest of the car; for the wheels, the makers’ advice is simply to wash them sooner after a drive on treated roads.
How we clean wheels on an exterior detail
Wheels come first on our exterior detail, with their own buckets and brushes, and the makers’ list shapes the rest: the wheels cool before anything touches them, the cleaner is mild and used exactly as its maker directs, soft brushes and sponges only, and a thorough rinse of the face and the inside of the barrel. RIAL asks that any specialist wheel cleaner be used strictly to its instructions, especially how long it is left on, and that is the rule we hold to.
Two more points from the makers. RIAL warns against car washes with rigid brushes, Kia against high-speed wash brushes, and GM says silicon carbide tire brushes in an automatic wash could damage aluminum or chrome-plated wheels. And RIAL says to touch up a chip in the paint finish with clear coat so corrosion does not start there. Our post on washing without swirl marks covers the washing order that keeps grit off the paint. If the car is parked in Franklin or anywhere else we cover, send us the year, make and model and we will quote the detail.
- No acid, alkaline or alcohol-based cleaners (RIAL, Kia, GM)
- No wire brushes, steel wool, abrasive cleaners, polishing compounds or solvents (Kia, Mazda, RIAL)
- Clean the wheel cold (Kia, RIAL)
- Mild soap or neutral detergent, a soft brush or sponge, a thorough rinse (Kia, Mazda, GM)
- Every two weeks, weekly in winter (RIAL); after salted roads (Kia, Mazda)
- Avoid car washes with rigid or high-speed brushes (RIAL, Kia, GM)
Sources
- RIAL, Care instructions for alloy wheels — Every two weeks, weekly in winter; inside and outside; no acids, alkalis or alcohols; cold wheels; soft sponges and brushes, no steel wool; follow wheel cleaner instructions; avoid rigid-brush car washes; touch up chips with clear coat
- Kia Owner’s Manual (2024), Aluminum wheel maintenance — Clear protective finish; no abrasive cleaner, polishing compound, solvent or wire brush; clean when cooled; mild soap; clean after salted roads; avoid high-speed wash brushes; no alkaline or acid detergents
- Mazda, 2016 CX-3 Owner’s Manual, Aluminum Wheel Maintenance — Protective coating; mild detergent after checking ingredients; no wire brush, abrasive cleaner, polishing compound or solvent; clean after dusty or salted roads
- General Motors Service Bulletin 18-NA-067, Excessive Brake Dust on Wheels (NHTSA) — Brake dust a normal characteristic of high-performance pads on 2014-2018 GM vehicles; soft cloth, mild soap and water; no acid cleaners, abrasive brushes or chrome polish on aluminum; silicon carbide tire brushes in automatic washes
- General Motors bulletin on brake caliper finish (NHTSA) — Acidic wheel cleaners may craze, crack, discolor or remove caliper finish; not covered by warranty; soap, water and a soft brush
- Metro Nashville Department of Transportation, NDOT to Begin Pre-treating Nashville Roads Tomorrow Morning (January 2026) — Salt brine pre-treatment; 100,000 gallons of brine solution and 40,000 gallons of calcium chloride for 2025-26
FAQ
Brake Dust and Alloy Wheels: What Makers Say — questions
How do you clean alloy wheels without damaging them?
Let the wheel cool, then wash it with mild soap or a neutral detergent, a soft brush or sponge, and a thorough rinse, inside and out. Kia, Mazda, RIAL and General Motors all warn off wire or abrasive brushes and abrasive cleaners, and RIAL says any specialist wheel cleaner must be used strictly to its instructions.
Can you use acid wheel cleaner on alloy wheels?
The makers say no. Kia warns that acid or alkaline detergents can damage and corrode a clear-finished aluminum wheel, RIAL rules out cleaners with acids, alkalis or alcohols, and a General Motors bulletin lists acid cleaners among what to avoid. Another GM bulletin says acidic wheel cleaners can damage brake caliper finishes too.
Is brake dust on wheels normal?
On the vehicles General Motors has addressed, yes. A 2018 GM service bulletin calls heavy brake dust a normal characteristic of high-performance pad material on 2014 to 2018 Buick, Cadillac, Chevrolet and GMC vehicles, made more visible by open-spoke wheels. GM’s advice is a soft cloth, mild soap and water, a rinse and a soft towel.
Should wheels be cool before you clean them?
Yes. Kia’s owner’s manual says to clean an aluminum wheel after it has cooled, and RIAL, the German wheel maker, says wheels should be cold when they are cleaned. After a drive, give the wheels time to cool before any water or cleaner touches them; we let them cool before a detail starts on them.
Can automatic car washes damage alloy wheels?
Some can. General Motors says silicon carbide tire brushes in automatic washes could damage aluminum or chrome-plated wheels. Kia advises avoiding high-speed vehicle wash brushes, and RIAL says to avoid car washes with rigid brushes. A hand wash with soft tools and a mild soap keeps the wheel’s finish clear of that risk.
How often should you clean car wheels?
RIAL, a German alloy wheel maker, says at least every two weeks and once a week in winter. Kia and Mazda both say to clean wheels after driving on salted roads, and Mazda adds dusty roads, to help prevent corrosion. Nashville’s roads are pre-treated with brine ahead of winter weather, so winter calls for more.