Cleaning

Car cleaning products: pick by the dirt, not by the brand

What is a car cleaner? A product that breaks dirt loose from a vehicle surface chemically instead of scrubbing it off. This category covers pre-cleaners, wheel cleaners, glass cleaners, all-purpose cleaners, insect removers, iron fallout removers and solvents for tar and adhesive. Which one does the job depends on the type of dirt.

Car cleaning products lift dirt off a vehicle surface chemically rather than wearing it away mechanically. The umbrella term covers pre-cleaners, wheel cleaners, glass cleaners, all-purpose cleaners, insect removers, iron fallout removers and the solvents for tar and adhesive residue. What sets them apart isn't the brand, it's what they attack. Which types of dirt a cleaner shifts comes down to its formula; some products combine several cleaning properties.

• Four types of dirt, four ways to attack them. Organic, mineral, oily, metallic — that's every group you'll find on a car. Once you've put the dirt into a group, the choice shrinks from the whole category to a handful of candidates. That's exactly what this page is built for.
• Concentrates pay off from the second car. The Koch-Chemie Multi-Purpose Cleaner „Mzr" All-Purpose Cleaner is diluted between 1:10 and 1:50, so one litre gives you up to 51 litres of cleaner. Ready-to-use spray bottles save you the mixing and are the easier call if you only do one car a year.
• The colour change shows the chemistry is working. Iron removers like the Koch-Chemie Reactive Rust Remover „Rrr" iron fallout remover turn purple as soon as they grab metal particles. So you can see on the paint where the fallout sits before you can feel it with your fingertips.

Detailing1's tip from the shop: What we see day-to-day: the most expensive mistake in this category isn't picking the wrong product, it's running out of patience. The dwell time you need is in the product instructions; that's when the active ingredients break the dirt down. Reach for the towel straight away and you drag hard particles across the paint and pick up swirls — fine circular scratches that show up as a spider's web in direct sun. The other half of the same rule: never let the cleaner dry on. Work on a cool surface in the shade, spray panel by panel rather than the whole car, and rinse while the surface is still wet. Chemistry that dries on leaves marks that are harder to shift than the dirt was.

Four types of dirt, each with its own chemistry

Every bit of dirt on a car falls into one of four groups, and each group has its own weak spot.

Organic is anything that was once alive: bug splatter, bird droppings, pollen, tree sap. Behind it are proteins and fats that break down in an alkaline environment. Alkaline means the cleaner sits above pH 7 and saponifies fats, turning them water-soluble. In practice, a baked-on wall of bugs runs off on its own after a few minutes' dwell time instead of smearing into streaks under the sponge. The products for this are under Insect remover.

Mineral is the opposite: limescale from hard tap water, water spots after drying in the sun, cement haze from the building site next door, road salt residue in winter. These deposits are alkaline, so an alkaline cleaner just bounces off. What works here is an acid that turns the mineral into a water-soluble salt. Put simply: the hard white spot becomes something that simply runs off with the rinse water.

Oily covers tar, bitumen, oil, silicone residue and adhesive left behind by badges or price stickers. Water and surfactants don't get far, because the residue itself repels water. You need a solvent that swells the stuff and takes it up. The Koch-Chemie Teerwäsche A „Tea" Bitumen & Tar Remover belongs in this group, as does the Koch-Chemie Eulex „Eu" Adhesive Remover for sticker residue and rubber marks.

Metallic, finally, means iron fallout and brake dust. Every time you brake, red-hot iron particles fly off the pads and burn into paint and wheels. An iron remover binds these particles with an active ingredient from the thioglycolate family, which clamps around each iron particle and makes it water-soluble. For you that means: what was baked on a moment ago bleeds purple and runs off before you even pick up the brush. The topic has its own page under Rust remover.

The rule of thumb is simple. Chemistry beats chemistry; against the wrong chemistry only elbow grease helps — and elbow grease on paint is always the more expensive route. We often see customers buying a third product from the same group when the dirt actually belongs to a different one.

The pH value tells you which cleaner will work

If you take just one number away from this category, make it this one: the pH value. It rarely sits big on the label, yet it decides between success and damage.

Alkaline cleaners sit above pH 7 and are the workhorse for organic dirt and traffic film. They cover most of a normal wash, from the pre-cleaner and all-purpose cleaner to wheel foam. The higher the value, the more grease they cut — and the more care you need around sensitive surfaces next to them.

Acidic cleaners sit below pH 7 and are the answer to mineral deposits and stubborn brake dust. They work fast but are unforgiving. On bright-polished aluminium, magnesium wheels and chrome, too long a dwell time can etch the surface dull, and that damage doesn't come back. So with acidic products the rule is: cold wheel, short dwell time, rinse thoroughly.

Neutral cleaners around pH 7 also need the right material approval. On ceramic coatings, wraps and anti-glare displays, what counts is the specific product approval and the care instructions for the surface. Acid-free doesn't automatically mean pH-neutral, either: the Koch-Chemie Magic Wheel Cleaner "Mwc" Wheel Cleaner works reactively against brake dust and, according to the product information, has a pH of 5.5.

The TUGA Chemie Alu-Teufel „Spezial"® (Green) Wheel Cleaner follows the same logic and is our best-selling wheel cleaner outside the Koch-Chemie range. The colour change makes it visible that it's working; on polished wheel lips, check the specific product approval.

One limit needs saying plainly here: no pH value in the world replaces dwell time, and no cleaner works better because you mix it stronger than recommended. Overdosed concentrates leave surfactant residue that pulls moisture from the air and attracts fresh dust within days. A lot of the questions we get about supposedly weak cleaners turn out to be a dilution issue.

Where the dirt sits helps decide the product

The type of dirt tells you which chemistry you need. The surface tells you which one you can get away with.

Paint is the most sensitive large surface on the car. Depending on the manufacturer, the clear coat on top is only around 40 to 50 micrometres thick — roughly half a human hair. Anything that attacks or scratches it can only be corrected by removing material, and there's only so much to remove. That's why on paint we stick to cleaners approved for it and keep to the dwell time in the product instructions. The products for chemical decontamination are under Paint cleaning.

Glass can take a lot more but needs something else: zero residue. A glass cleaner has to flash off quickly and evenly, otherwise you get streaks that are especially annoying with the sun low in the sky. The Koch-Chemie Glas Star „Gla" Glass Cleaner Concentrate is the concentrate for anyone doing a lot of windows, the Koch-Chemie Glass Cleaner „Gc" Glass Cleaner the ready-to-use option for quick top-ups.

Wheels are the other extreme. That's where heat, brake dust and road salt meet, and the finishes vary: powder-coated, painted, polished, chrome-plated, matte. Even on painted factory wheels the product approval has to match; on polished and matte finishes, check the restrictions that apply with extra care. If in doubt, check the approval for your wheel finish and keep to the dwell time in the product instructions.

For exterior plastic and rubber — wheel arch liners, trim strips, seals — the product approval and care instructions have to suit the surface. The protection step that follows is under Care products.

For surfaces that don't fit any specialist group, there are the all-rounders. The Koch-Chemie Allround Surface Cleaner „Asc" All-Purpose Cleaner handles sills, floor mats, engine covers and plastic add-on parts in one product. You'll find the whole group under All-purpose cleaners and the special cases under Specialist cleaners.

From coarse to fine, never the other way round

Cleaners don't work in isolation, they work in sequence. Flip the order and you do the job twice.

Start with the wheels, and do them before the wash. Wheel cleaner tends to splash, and whatever lands on paint you've already washed has to come off again. Second reason: the cleaner needs a cold wheel, and you're more likely to have one at the start of the session than after twenty minutes in the sun.

Next, the pre-cleaner goes onto the dry, unwashed car. Its job isn't to get it clean but to knock the dirt down: it loosens the heavy traffic film so your wash mitt drags fewer particles across the paint later. The Koch-Chemie Vorreiniger B „Vb" Pre-Cleaner is our best-seller at this stage, the Koch-Chemie Pre-Foam efficient „Pfe" Pre-Cleaner & Insect Remover the version that takes care of bug residue at the same time.

Only then comes the actual wash with shampoo and two buckets. Anything you've already removed chemically can't scratch you any more. The products for this are under Car wash.

After the wash and before any protection step comes decontamination, in this order: iron remover for fallout first, then solvent for tar, and finally clay for whatever's left. The order isn't a ritual. Each step takes work off the next, and your clay lasts longer if you're not dragging it through tar spots.

Right at the end comes building up, not taking off. A freshly decontaminated surface is as receptive as it gets — and as unprotected as it gets. Day-to-day at Detailing1 we regularly see cars where the cleaning was meticulous and the protection step got skipped — four weeks later the paint looks just like before, and all that work went down the drain.

Concentrate or spray bottle: your usage decides

Our range in this category is broad, and the way it's weighted says something about the market.

SONAX makes up by far the biggest group and covers every price point, from entry-level products to the PROFILINE series. Koch-Chemie comes second in size but dominates the best-seller list. Then there's GYEON, CarPro, Soft99, Meguiar's, D-CON and TUGA Chemie, each with smaller, clearly focused line-ups. The range runs from the handy spray bottle to the canister for the professional detailer.

The top seller in the whole category is the Koch-Chemie Green Star „Gs" Universal Cleaner, an alkaline concentrate that, depending on dilution, goes from gentle interior cleaner to heavy-duty wheel and engine bay cleaner. That range is exactly why it sits at the top: one canister replaces three spray bottles, and you control the strength yourself.

Right behind it is the Multi-Purpose Cleaner „Mzr", which is milder and so ends up in the interior more often. If you know both, you use Green Star for outside and down low, and the Multi-Purpose Cleaner for inside and up high.

Concentrate or ready-to-use comes down to volume in the end. One car, two to four washes a year: spray bottle. Several cars in the household, monthly care, or a used car that's getting a full going-over once: concentrate. The lower price per litre is one argument; the flexibility in dilution is the other, and often the more important one.

What this category deliberately doesn't cover is polishes and sealants. A cleaner takes away, it doesn't lay anything down. As soon as the dirt can't be dissolved chemically and is sitting in the paint, this page's job ends and the polish takes over.

These three cleaners belong in your cupboard first

If you're just starting out, you don't need a collection. Three products cover everyday use.

First, an alkaline pre-cleaner. It's the step with the biggest impact on paint condition, because it removes the particles your wash mitt would otherwise drag around. Second, an acid-free wheel cleaner with a colour change; for iron particles on paint, the specific product also needs explicit paint approval. Third, a universal concentrate for anything that isn't paint, glass or wheels.

For high-mileage drivers and commuters, add a fourth: the insect remover. Between May and September it's the one cleaner you'll need every week, and the sooner the splatter comes off, the less time its acids have to eat into your clear coat.

For detailers and anyone working on several cars a day, the maths is different. There, the canister pays off for the two most-used products, while the specialists for tar, adhesive and fallout stay in small sizes. You don't reach for them often, and opened solvents age faster than water-based cleaners.

If you're not sure, don't go by the brand, go by the problem. Describe the dirt, put it into one of the four groups, and the choice narrows itself down. What we see again and again at Detailing1: most bad buys don't come from bad products but from dirt that belonged in a different group.

The rest of this page goes deeper. You'll find the sub-groups under All-purpose cleaners, Specialist cleaners, Insect remover, Rust remover and Paint cleaning. What happens before is under Car wash, what comes after under Care products.