What Kind of Soap Should You Use When Washing Your Car?

April 19, 2019

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So you want to wash your car like a pro, but you have no idea what kind of soap you should use. A lot of people say to just use dish detergent, but is that really safe for your car?

Save the Dish Detergent for the Dishes

We have all been in that situation. We are hustled into having our car washed in the name of a charity or some funding some local scholastic event. And you have all these car washers out there with their simple sponges and buckets of dish detergent mixed with warm water. 

They simply layer on the soap and spray it off, a fun little venture for $10. But, what you don’t realize is that dish detergent is full of detergents that strip off all the protective sealants and waxy residues that make your paint shine and bead off water. These are important protectors of your paint and finish not the grime that makes cars look dull. In fact, cars washed in dish soap look very dull.

This may not be a huge problem if you are going to apply a fresh layer of hard paste wax immediately after. But, it does become a big problem if you don’t because water will start to react with your paint and soften it. The UV-rays from the sun will burn out the vivid colors and dull your paint, practically overnight. 

Making matters worse, any tree sap, bird droppings, or acid rain can start eating rust spots into your paint relatively quickly. You will also have a greater chance of eroding the smooth surface of the paint just from the dust blowing around in the air at high speeds. For all these reasons, it makes sense to use special soaps designed for automobiles that are designed to maintain a perfect finish and retain the value of your vehicle.

What Are the Properties of a High-Quality Car Wash Soap?

A high-quality car wash soap is different than the many kinds of soaps that you use in your daily life. You use hand soap with pumice to cut out the grease after working on your car. You like a nice moisturizing soap for your face. When it comes to laundry, you want something full of detergents and other special additives to brighten whites and keep your colors rich. A car soap, however, has lots of bubbles and is lubricious. If it is pH balanced and biodegradable, this makes it even better.

Suds are very important for a car wash soap, often called a shampoo, because it has that effervescent type of mechanism to envelop and lift dirt away from the surface. This is important because the particles can otherwise cling to the car and scratch the paint when you pass your sponge or wash mitt over it. 

For the same reasons, car shampoo should be lubricious. You can tell the difference between a high-quality shampoo and an inferior brand by simply rubbing the soap between your fingertips. The high-end car soap will be slick and slippery. The cheaper kinds will feel gluey and have a caustic drying effect on your skin. This lubrication makes it easy to effortlessly glide away dirt particles without risking a buildup and residue that clings and scratches the surface of the vehicle during the wash cycles.

A biodegradable car shampoo is better for the environment and is generally safer for your lawn, pets, and family. This will also make you feel more comfortable working around it because it will contain no toxic chemicals. Most of these biodegradable cleaners contain vinegar, denatured alcohol, various types of oil, and plant-based surfactants. This will make you feel better about eating those tomatoes in your garden.

The correct pH balance is important because an acidic soap will soften the paint of your vehicle. The residue can cling to the surface and make it easier for debris to scratch the paint or become embedded. A car wash soap with a neutral pH will provide the best results and keep that hard finish glowing. 

Types of Car Wash Soaps

General Car Wash Soaps

When it comes to car wash soaps, there are also three major categories: general wash, wash and wax, and strip shampoos. The general wash is fine to apply any time because it is gentle enough to wash away the dirt clinging to the wax or sealant without stripping these protection compounds off the vehicle. They may have conditioners to help restore the sealant or wax coating to a new luster instead of stripping it away. 

Wash and Wax Car Wash Soaps

The wash and wax formulas will not only leave your current wax intact, but they will also add an additional layer of wax to ensure a perfect bead and shine. These are ideal when you already have a solid paste wax base, but it needs some refreshing. 

Strip Shampoo Soaps

strip shampoo is something that you can use every 6 months or so to take all the wax or sealant off your vehicle. As long as you follow up with an immediate coating of fresh paste wax, you will not damage the paint. 

Although many soaps out there can strip the wax off, including dish detergent, the specially formulated car washes provide the gentle care you need to prevent damage to paint surfaces. After all, soap can act like a solvent and dissolve or soften the outer layers of the clear coat if you use something too acidic or scratch easily if you use something that lacks lubricity. 

What Method of Car Washing is Best?

The best method that many detailers use is the two bucket wash mitt method. When they use this method, they have two 5 gallon buckets of water. One has the car wash shampoo dissolved in it and suds up very nice. The second is there to rinse out the glove between applications. 

You should always spray off any visible layers of grime with a hose first. Don’t use a power washer because that is overkill and can do more damage than good. You should then work from the top down, rinsing the wash mitt in the rinse bucket to free any particles between areas. The roof, hood, trunk, doors, front bumper, and rear bumper should be cleaned in that order. Then, you can use a special brush for the wheels to avoid brake dust contamination.

The contamination is actually the rotors being worn down by the friction material more than the pads themselves. If you look at your rotors, you will usually see that the pads eat relatively deep into rotors and leave an outer raised edge at the end of pad life. Adding a special sealant to the wheels may help to repel the buildup of brake dust to ensure that those freshly washed wheels don’t look dirty a few days later. 

And that is all there is to it when using the correct car wash shampoo for your vehicle and the professional methods.

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About The Author



Hey! My name is Stephen. I love cars, but most importantly, I love clean cars. In fact, my first job was detailing cars at a Ford dealership.