Should I use pH neutral car wash for ceramic coatings?

Quick answer: Yes -- a pH-neutral shampoo is perfectly fine for routine washing of a ceramic coating, but it is not magic and it is not the only safe option. Almost any car shampoo from a reputable maker will do the job. What you actually want to avoid is using the wrong product entirely -- strong alkaline degreasers, acidic wheel cleaners or washing-up liquid as your everyday soap. Keep the aggressive stuff for targeted jobs.

Yes and no. Mostly yes.

The honest answer is that pH-neutral is a nice-to-have, not a must-have. What you should really reach for is any car shampoo made by a reputable manufacturer to be safe on paint. It may be pH-neutral; it may not be. Either way it will be fine on the coating.

What "pH-neutral" actually tells you

"pH-neutral" has quietly become shorthand for "safe for cars", and plenty of brands print it on the bottle because it sells. Is it genuinely important for a coated car? Not as much as the label implies. There are good reasons to use shampoos that sit either side of neutral. Citrus-based cleaners shift oil and tree sap well precisely because they lean acidic. A lot of soaps have real cleaning bite because they lean mildly caustic, and that is fine too, provided you do not overdo the concentration.

A ceramic coating is a hard, cured layer of silica sitting on top of your lacquer. A single routine wash with a slightly-off-neutral shampoo at the right dilution is not going to touch it. Coatings get tired over months and years from UV, road grime and repeated contact, not from one wash with a soap that measured pH 9 instead of pH 7. The pH panic is mostly marketing dressed up as chemistry.

Where the real damage comes from

Every week we see cars come into the workshop in Chelmsford with damage to plastic trim, window rubbers and chrome -- staining, white bloom and outright chemical burns. It rarely comes from someone's choice of bottled car shampoo. It comes from the fellas by the side of the road who hand-wash your car for a tenner. One of the ways they clean so cheaply and so fast is by mixing soap at double or triple strength, or simply using neat wheel cleaner as a general shampoo.

Make a soap very caustic and it stops being a soap and starts being a stripper. As Barry would say, "

Tom, our operations manager, makes the point that the coating is usually the last thing to suffer in these cases. The silica layer shrugs the harsh chemical off; it is the surrounding rubbers, the unprotected plastics and the polished metal that take the hit. We have re-trimmed and re-dressed more weather strips ruined by aggressive "valeting" than we can count, on cars whose paint was still in good order.

The washing-up liquid temptation

Hands that do dishes can be soft as your face, but dish soap is harsh stuff -- it is engineered to cut baked-on grease, and it often contains salt as a thickener. On the first sunny weekend of the year, the kids are out, the bucket comes off the shelf and someone reaches for the Fairy because it is right there under the sink. That will do the job, won't it?

It will, sort of. It probably will not do real harm the first time or the second. But as a long-term habit it is a poor choice: dish soap is good at lifting grease, which means it is good at lifting the very oils that keep trim and seals supple, and over a coated car it can leave the surface squeaking and dry rather than slick. The coating itself will shrug it off; the rubbers and plastics around it will not be as forgiving.

Car shampoo is not expensive, and we have never really understood the urge to use dish soap and floor cleaner to save a few pence. Usually it is convenience rather than cost -- it is what is already in the cupboard, and it saves a trip to Halfords. But car shampoos are not rocket surgery to make. Next time you are doing the weekly shop, take a detour down the motor accessory aisle and grab a bottle. Even a supermarket own-brand car shampoo is a world apart from Mr Muscle Power Clean.

The supermarket shop: everything a coated car needs

We had a look round Asda, Tesco, Morrisons and Sainsbury's to see what you could realistically buy on a normal shop. As far as we can tell, all of them except Sainsbury's stock the four things you actually need to wash a coated car safely:

• A couple of plastic buckets -- use two, one for clean soap and one to rinse the mitt, which is the heart of the two-bucket method and the simplest way to avoid wash marring.
• A car shampoo -- Car Plan, Armour All, Triple Wax, Demon and Simoniz all turn up on the shelves, and any of them is perfectly adequate for routine washing.
• A microfibre wash mitt -- far less likely to drag grit across the paint than a sponge. Asda sell one under their Auto-Drive label; Tesco and Morrisons stock a Simoniz mitt.
• Microfibre drying towels -- the large ones are easiest, and a pair will see a whole car dried.

The supermarkets also sell chamois and synthetic chamois leathers, which will do the job but are not our first choice on a coated car -- a plush microfibre towel is kinder and lifts standing water faster.

Method matters more than the bottle

Here is the part the marketing rarely mentions: how you wash matters far more than whether your shampoo reads exactly pH 7. The fastest way to put swirls into a coated car is a single bucket, a sponge and a hurried circular motion in direct sun. The slowest way to wear a coating out is two buckets, a clean mitt, straight-line strokes, plenty of rinse water and a soft towel to finish.

Spend nine minutes