
Originally Posted by
Michael Stoops
Dish detergent is highly effective at stripping grease, and if it strips grease it will strip wax. A quality car wash shampoo won't strip wax. That alone should tell you which product you want to use to wash your car.
Now, we've said this before and we'll say it again - using dish detergent to wash your car is not going to destroy your paint, plastic, vinyl, rubber, etc if you follow each wash with a full compliment of wax, vinyl and rubber dressing, etc. We've got a forum member who has basically proven this since his father used nothing but dish soap on his car, but otherwise babied the car with very regular surface treatments.
But the big problem is for the "average" consumer who never does anything more than wash the car - they can't be bothered with any of the "details' of detailing and they won't regularly apply a dressing to the trim, vinyl, etc. Then they wonder why all that trim has turned white in a couple of years. We've seen these cars come into our garage where the plastic cowl is almost white, and it comes from neglect. And neglect isn't just not dressing it, it's using products that can speed up the drying out of the material.
People think of things like vinyl, leather, paint, etc to be "dry" but in truth they aren't. Unless you let them "dry out". Ever seen a piece of leather that's really "dried out"? Looks a bit different than the seats in your new car, doesn't it? Ever worked on really dried out paint? It pulls the lubricants right out of the paint cleaner or compound you're working on and the product gums up on the surface. Ever try to apply a pure polish to a dried up gel coat? The gel coat color is instantly revitalized, but the pure polish is just soaked up by the finish.
Paint, and especially gel coat, is actually quite porous and it will take in a bit of these oils. Over time, it can, will and does dry out if not taken care of. There is no doubt that a modern clear coat is far more durable and resilient than earlier single stage lacquer paints, but they are not impervious to the ravages of time and the environment.
We're huge fans of simply following a "best practices" philosophy when taking car of your car, so we'll finish this the same way we started: Dish detergent is highly effective at stripping grease, and if it strips grease it will strip wax. A quality car wash shampoo won't strip wax. That alone should tell you which product you want to use to wash your car.