Pressure Washing A Car [Mega Guide & FAQ]

Washing your car can be very rewarding, but it can also be very time-consuming. Having the right tools will make it much quicker and easier to wash your car.

When you try to wash a car using a garden hose, the water pressure is almost non-existent.
The hose will get the job done for cars with light pollution, but as soon as you come across stubborn dirt, it takes hours to wash.

Using a pressure washer will significantly decrease the time that it takes to wash your car.
It will open up the possibility of using snow foam which will loosen up the dirt and let you blast the dirt off quicker than using just a pressure washer.

Owning a pressure washer is crucial if you want to get professional results in a quick time.

Is pressure washing a car good or bad?

Most things in life are both good and bad. It’s the same for the pressure washer.

Pressure washing a car is neither good or bad. You can misuse a pressure washer and cause a lot of damage, but you can also use it correctly and achieve great results.

Here are some common reasons why pressure washing a car can be good or bad.

Speeds Up The Wash Process

Pressure washing a car definitely speeds up the whole wash process. It isn’t however, a complete replacement for the wash process.

Thanks to the high-pressure jets, during the pre-wash stage, your pressure washer will remove loose contaminants from the surface of your car.

If your car is heavily contaminated and caked in stubborn dirt, you will want to use the foam cannon attachment.

Covering your car in snow foam and letting it dwell for a little while will loosen up the dirt and make it easier to rinse off.

Using a pressure washer, you will be able to get the car 80-90% clean. You will still need to hand wash the car, rinse it off and then even dry it if you want to achieve the best results.

If you want a 3 stage wash process that uses only the pressure washer to wash the car, AutoGlym Polar Series will allow you to do just that.

Minimizes Paint Marring

Anytime that you come into contact with the paintwork of a car, you risk scratching it.

The risk of scratching it will increase tenfold if you touch the car when it is dirty. Just imagine all the micro scratches that occur when you draw childish illustrations on a dirty car.

Thankfully, using a pressure washer you drop the need to touch the car while it’s caked in mud.

This is another reason to use snow foam. It lubricates the panel and uses cleaning agents that loosen up and helps to rinse dirt off your car before the contact wash.

Washing off the majority of the dirt before you even touch the car will significantly decrease the chances of marring the paint.

Cleans Stubborn Dirt Without Touching It

On a similar topic to minimizing paint marring. Using a pressure washer will allow you to clean stubborn dirt without even touching it.

How many times have you tried to scrub bugs and tar from your vehicle with little to no luck? Using snow foam and blasting them with the pressure washer will need less effort and limit the number of scratches you create at the same time.

Risks of Further Damaging Your Vehicle

This is the first big negative on the list but you don’t really need to worry about it.

So many people are scared that a pressure washer will destroy their paint job, but it’s something that’s often blown out of proportion.

If you take a pressure washer that’s too high pressure to your car, you will be able to create dents or blast the paint off.

That being said, you’ll probably never own a pressure washer that’s capable of doing this. Just stick to our recommended pressure washers and you’ll be fine.

Working on a damaged car is slightly different.

If you’re working on a car where the paint is peeling or there are rust bubbles, you will have to pay a lot more attention.

Going close to these cars and blasting the damaged areas with water will result in further damage. To avoid this, use really low pressure, avoid it altogether or leave it for the contact wash.

If you’re detailing as a business, you need to learn how to wash damaged areas. If you don’t, you’ll learn the hard way, when your business has bad reviews and many repair bills.

Requires a lot of water

When pressure washing a car, you’ll use up a lot more water. It’s inevitable.

If you live in an area where there are water restrictions, or if you pay water rates, it may be best to choose another wash method.

Using a wash method such as a Rinseless Wash or Waterless wash will limit how much water you use, but they can only be used on cars with light pollution.


Basic pressure washers aren’t the most expensive pieces of equipment in the world, but the costs can quickly add up.

You may pay $100 for an entry-level Karcher K2. You’ll then want to buy a foam cannon at $40 and a snow foam that comes in around $20-$40.

All of a sudden you’re almost $200 into washing your car.
That’s with a cheap pressure washer without considering electricity, water rates, and other accessories.

Pressure Washer Accessories for Car Washing

I’ve already made it clear that pressure washers allow you to use foam cannons and snow foams. There are also many other accessories.

If you want to use the majority of accessories that are developed by third parties, you will want to get a pressure washer from one of the leading brands, such as Karcher or Nifilisk.

This is because each pressure washer has different connections.

Accessories are developed and made so that they’re able to connect to the most used pressure washers.

Foam Cannon

Autobrite Foam Cannon

I absolutely love foam cannons.

I had a very cheap pressure washer and the reason I upgraded was so that I could get a foam cannon.

Foam cannons allow you to spray a thick layer of snow foam onto your vehicle. This layer of foam will work to break up dirt and loosen any stubborn grime.

Most foam cannons are like each other. The only variations will be the shape, size and build quality.

Looking for recommendations? I have the Karcher FJ6, it was all I could get at the time but it gets the job done.

If you’re willing to spend more money, the Autobrite foam cannon is the most recommended among professionals.

In terms of snow foams, I’ve compiled a list of the best snow foams on the market.

If you want to save yourself a click and some reading, Bilt Hamber Auto Foam is the best in terms of both cleaning power and value for money.

Detergent Tank

Karcher Detergent Tank

A detergent tank is somewhat similar to a foam cannon.

Foam cannons can double up as a detergent tank if you change up the product to a car shampoo.

Detergent tanks cannot double up as a foam cannon. The tanks also produce a lot less suds.

In the long run, you’ll get better value for money if you invest in a foam cannon and dilute the products yourself.

Car Wash Brush

Pressure Washer Car Wash Brush

Most people see these brush type accessories and take it straight to their paintwork. I wouldn’t dream of doing that.

Pressure Washer Brush accessories are very hard bristled and are likely to scratch your paint.

I got a free brush with my Karcher and the only thing I use it for is cleaning the tires or cleaning plastic/carpeted wheel arches.

It’s not an attachment I’d go out of my way to buy, only the foam cannon is. But if you get one free when buying a pressure washer, there certainly are uses for it.

How To Pressure Wash A Car

Pressure Washing Car

As before mentioned, pressure washing a car is for pre-wash and rinsing purposes.

You can apply car soap using a pressure washer but you should always perform a contact wash too.

Below are the stages of washing a car and how you should use a pressure washer to wash your car.

Pre Wash:

  1. Plug the Pressure Washer into an electric source, connect your garden hose and foam cannon.
  2. Spray Snow Foam onto the vehicle. Top to bottom, on the wheels too.
  3. Let the snow foam dwell for the manufacturers’ recommended time.
  4. Rinse the car off with water using your pressure washer

If you don’t have a foam cannon, rinse the car with water using the pressure washer. It will remove some contaminants and still lubricates the panel for the next step.

Contact Wash: You will not use the pressure washer during the contact wash stage unless you have a car shampoo that is applied using the pressure washer.

If the pre-wash stage done its job, you shouldn’t need to put too much effort into the contact wash.

I recommend using the 2 bucket wash method to wash your car.

Post Wash: Thoroughly rinse the vehicle from top to bottom using your pressure washer.

Make sure that you rinse every crack and crevice so that there is no soapy residue left anywhere on your car.

After you have thoroughly rinsed the car, I suggest drying your vehicle using microfiber towels. This will ensure that no water spots or streaks are left behind.

Frequently Asked Questions

Pressure washers are very simple and straightforward. Despite being a simple piece of equipment, people still manage to overthink.

Below is a list of common questions that are asked about pressure washing cars.

What is a safe psi to wash a car?

When choosing a pressure washer there are 2 things to keep in mind.

PSI = Pounds Per Square Inch
GPM = Gallons Per Minute

The PSI dictates the force the water will leave the tip of the washer.
The GPM dictates how much water the washer will release.

You can multiply these together to get cleaning units. PSI x GSM = Cleaning Units

For washing a car you will want a pressure washer between 1200-1900 PSI.

Remember that different attachments and nozzles will also dictate the amount of force that the water leaves the tip at.

Can you pressure wash a car engine?

To cut a long answer short, yes you can pressure wash an engine bay.

Should you wash an engine bay? Well, that’s up to you.

Taking a pressure washer to the engine bay and more specifically, engine block can be very risky.

The engine bay is where the fuse box and many important electrical components are. Introducing water to these components can seriously mess with a car.

If you do decide to take the pressure washer to it, make sure that you use a low-pressure setting and are prepared for potential issues if you do it wrong.

I’ll stick to the garden hose, degreaser, and some cloths. It’s much safer.

Can you pressure wash car seats?

You certainly don’t want to pressure wash car seats.

Most modern seats also have electrical connections and components within them. They’d also take an unbelievable amount of time to dry.

To wash your car seats properly, you should use a wet & dry vacuum or some sort of upholstery/leather cleaner.

Don’t waste your time pressure washing your seats. It’s almost all negative.

Can you pressure wash car mats?

Depending on the material of the car mat, you may want to pressure wash them.

If you have rubber car mats, take them out of the vehicle and cover them in an all-purpose cleaner, agitate it using a detailing brush and then rinse them off using your pressure washer.

Repeat these steps until your car mats are as clean as you want them to be.

Carpet floor mats, on the other hand, should be brushed using stiff metal and then washed with a wet and dry vacuum.

Pressure washing them may work, but they’d take a lot longer to dry.

Can you pressure wash car carpet?

Like carpet floor mats, you should take a little more care with the carpet.

If you’re working under a time limit, washing the carpet by brushing, hoovering and then performing a wet & dry will give you the best results.

To pressure wash a carpet, you’re best taking it completely out of the vehicle, which for a lot of people will be too much effort on its own.

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About the Author: JoshWilkins

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