One of the steps towards proper car maintenance is washing. Car washing improves a car’s appearance by removing dirt and contaminants from the surface. More than the aesthetic effect it has, it also ensures that the paint job lasts longer by removing destructive agents from the car exterior. There are dedicated cleaning shampoos made exclusively for auto detailing, but many still wonder if they could improvise by washing with hair shampoo.
Hair shampoo is not good to wash cars with for many reasons. It contains abrasive ingredients that irritate car paint and causes it to fade. It is not formulated specifically for car washing, so it lacks the lubrication to clean without causing scratches to the car surface.
The importance of choosing the right cleaning product for a car cannot be overstated. Knowing the properties and effects of a cleaning product will go a long way in helping to preserve an automobile’s look. Let’s take a close look at some essential details.
Is Shampoo Good for a Car Wash?
Regular shampoo is not suitable for washing a car for many reasons. It does not lubricate the car’s surface enough to prevent scratches during the contact wash phase. Moreover, hair shampoo will remove car wax and other protective layers due to the oil-dissolving ingredients.
Car shampoo is significantly less abrasive than hair shampoo, and it typically has more lubrication, so it doesn’t cause scratches when used to wash cars.
Hair shampoo is specifically formulated to loosen oil and dirt from hair – which is a protein structure – such that the dirt can be easily washed out with water.
Car paint isn’t a protein structure, and it doesn’t get contaminated by the same agents that contaminate human hair, so it’s not the best idea to wash a car with hair shampoo.
Moreover, waxed car exteriors are likely to be degraded more rapidly by hair shampoo. This is due to the chemical ingredients used to make it strong enough to remove grease and other dirt from hair.

A compromised wax layer exposes the paint directly to the destructive effect of grime, water, sunlight, and other contaminants.
To prevent exposure of the paint layer of a waxed car to harmful contaminants, you should steer clear of alternative car cleaning products like hair shampoos that may reduce the lifespan of the wax layer.
Furthermore, hair shampoo formula is not as effective as dedicated car shampoo in washing away dirt, and grime from cars. There’s a lower level of efficacy when hair shampoo is used in place of car shampoo.
Although there is no perfect substitute that can offer the same level of cleansing and safety for the clear coat like car shampoos and dedicated car wash soaps, few soap alternatives are suitable in cases of emergency where these products are not available.
The major downside to using shampoo alternatives is the high risk of scratching. Some, not all, car wash substitutes are strong enough to break down stubborn car paint contaminants, but the strong chemical ingredients pose the risk of paint damage.
What Is a Good Substitute for Car Wash Soap?
For a hand wash, there’s no better substitute for car wash soap. It is formulated to be tough on dirt, grime, and other contaminants and gentle on car paint. Due to its gentleness on the finish, car wash soap is less likely to cause scratches, provided a soft washing mitt is used.
Car wash soap substitutes, on the other hand, are more likely to affect the clear coat. When these soaps are used with a washing mitt, there is usually an increased chance of paint scratching and damage to the protective wax layer.
Nevertheless, car owners can improvise with some other cleaning products when using other washing methods apart from hand wash. Here are some of them.

Laundry Detergent
Laundry detergent is one of the most effective alternatives to car wash soap. Its chemical concentration is potent enough to break down and wash away dirt, grime, and other strong contaminants.
However, the continual use of laundry detergent can negatively affect the paint job because of the abrasive chemical content.
If you ever have to use laundry detergent, stick to a mild option and dilute well with water.
Dish Liquid Soap
Dish liquid wash soap is another decent substitute for car wash soap when you’re not carrying out a hand wash, and it’s readily available in many home kitchens.
It contains microscopically abrasive ingredients that make it highly effective in cutting down grease. These ingredients make it suitable for cleaning grease and oil stains off cars.
However, these same ingredients give the soap paint-stripping properties, especially when used repeatedly or in highly concentrated quantities. Moreover, when dish soap is applied with a washing mitt, it increases the risk of scratching the car.
It should be watered down as much as possible to protect a car’s paint layer when washing with dish soap. Dish liquid soap cannot replace car wash soap. It is only suitable as a short-term substitute.
I have written an in-depth article about washing a car with dish soap, and if you should do it, here. Make sure to check it out!
Hand Soap
Hand soap is a highly recommended car wash soap substitute because it is reasonably mild. It is not as damaging to clear coats as many of the other cleaners.
With this advantage comes a downside. Hand soap is not nearly as potent in dirt removal as other soaps. Caked mud, oil, and other greasy contaminants prove too stubborn to be washed off by hand soap.
Also, it typically comes in small quantities that may be insufficient for a car’s surface area.
Wheel Cleaner
Wheel cleaner is quite similar to car wash soap in its formulation. It contains some extra ingredients to make it more suited to automobile wheels.
Wheel cleaner can be pretty acidic in its composition, and as such, it is not recommended as the safest resort. Still, when it is absolutely necessary to use wheel cleaner as a substitute for car wash soap, you should adequately dilute with water.
Interestingly, not all wheel cleaners are acidic. Acid-free and pH-balanced wheel cleaners are tough on dirt and relatively gentle on the paint job.
All-Purpose Cleaner
The highlight of all-purpose cleaners is that they are versatile formulations used to clean various household elements, from countertops to floors and furniture.
Strong concentrations will cut through oil and grease stains easily without the need for much manual input, but they can likewise irritate car paint.
Cleaners like bleach, toilet cleaners, and stove cleaners are very highly concentrated, and they will damage your clearcoat. Furthermore, some household cleaners tend to leave films on surfaces.
To prevent damage to the paint job, water down with water as much as possible or simply stick to mild all-purpose cleaners.
Can I Wash My Car With Just Water?
Considering the damaging effects of many car wash soap alternatives when used repeatedly, you may wonder if it’s safe and efficient to wash your car with just water.
Washing a car with only water is sufficient to get rid of dust from a car’s surface. However, it does not effectively remove oil, grease, and other deep-seated dirt. Thorough cleaning requires car shampoo or any other related soap product that can break down grease, grime, and other water-resistant contaminants.
There are different reasons why you may want to wash your car with just water. The most likely reason is to save money. You may have just run out of car shampoo, and you need to wash your car urgently. You might also be running on a budget, with insufficient money to buy a car wash soap or shampoo.
In certain municipalities in the United States, some laws don’t allow car wash soaps to run into drains and sewers because of the harmful environmental impact. You’re compelled by law to wash your car with just water or visit a professional car wash in such a case.
Another reason could be that you’re critical of the effect of car wash products on your clear coat. While car shampoo is reasonably safe to wash a car with, several alternative cleaning agents contain chemicals that can damage car paint and degrade car wax.
There are some factors to consider when washing a car with only water. I have written an article on how to wash your car just with water, so be sure to check it out here and follow the instructions.