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A big trend among amateur detailers is the move towards pH neutral car shampoos.
But what does this mean and why is it good for cars? Keep reading for the full pros and cons.
What Does pH Neutral Car Shampoo Mean?
Just in case you weren’t paying attention in chemistry class, the pH (potential of hydrogen) scale ranges from 1 to 14 and measures how acidic or alkaline a solution is.
Key numbers in the pH scale are:
1 – Highly Acidic
7 – pH Neutral (neither acidic not alkaline)
14 – Highly Alkaline
Anything in the middle of the scale is generally considered safe, but as you progress to the top or bottom of the scale, products can become harmful to the skin or products they are used on.
Moving away from the centre also has benefits when it comes to cleaning as the corrosive properties also attack dirt.
For example, oven cleaners tend to be highly alkaline as this is good at removing organic dirt such as grease.
However, as technology has advanced, many manufacturers have managed to create highly effective car shampoos that are still pH neutral.
This means they can be gentle on the cars paintwork and any layers of wax/sealant that you’ve applied, whilst still being effective against mud, bird poo and other dirt that accumulates on the vehicle.
What are the pros and cons of a pH Neutral Car Shampoo?
Here is a run down of the pros and cons of using a PH neutral shampoo:
A well formulated pH neutral car shampoo won’t contain any of the harsh chemicals that some cheaper car shampoos contain.
Whilst it’s unlikely that an alkaline shampoo will have any immediate impact on your vehicle, over time it can cause premature aging of the paintwork.
Most people will choose a pH neutral shampoo as it’s suitable for use after using a wax or sealant without impacting it.
The formula will still remove dirt but leaving the wax intact.
It’s also good for use on top of a ceramic coating, although there is less risk of washing this off anyway.
A benefit of pH neutral shampoo that you might not consider is that it’s better for your skin.
Your skin is slightly acidic so the best types of product for your skin will be very similar, whereas many car shampoos are more alkaline.
Whilst you shouldn’t go washing your skin with it each day, if you spend a lot of time washing your car, it will be much milder.
If you’ve visited an automatic or touchless car wash, these will often use an acidic prewash to tackle the salt and grit, followed by an alkaline shampoo for mud, bird poo, etc.
This is because they are designed to be quick and effective with no soaking.
When using a pH neutral shampoo, you’ll need to allow extra time for the formula to tackle the dirt.
The truth about pH neutral car shampoos is that they won’t tackle the dirt alone as an acidic or alkaline formula would.
It requires more elbow grease on your part to get at the dirt.
With this in mind, you should invest in a proper wash mitt and not use a sponge as this can wipe dirt particles across the surface and cause small scratches.
Which pH Neutral Car Shampoo Do You Recommend?
My personal favourite is the Autoglym Bodywork.
It provides a good level of suds that allow the wash mitt to glide over the surface, whilst still being easy to rinse thanks to the water repellent barrier that the formula creates.
It’s also very affordable and there are a variety of options from 500ml up to 2L. With the highly concentrated formula, this will last a long time.
If you want to see other products, I wrote a full guide to the top pH neutral car shampoos.
Can I Use Household Detergents to Wash my Car?
I would not recommend using household detergents on your vehicle as these have been designed for a different use case.
Washing up liquid is not suitable for use on cars as it uses an alkaline formula to tackle tough grease that accumulates on ceramic and stainless-steel kitchenware.
This needs a much tougher formula than what’s required for washing mud and bird poo from your plastic clear coat.
If you are desperate and do need to use a household product, baby shampoo is the best choice with a pH formula. However, it’s usually low foaming so still isn’t ideal.
Kieren is the founder and editor-in-chief of Auto Adviser. Kieren created the site to share his passion of cars that began long before he passed his driving test and is now a recognised contributor in the industry. Outside of cars, Kieren loves drinking coffee and travelling to far-off lands.