Can You Use Car Wash Soap in a Pressure Washer?

Wondering if you can use car wash soap in your pressure washer to clean your car? Cleaning your car with your pressure washer is possible. However, you do need to check to see if your washer has a soap tank. Also, the soap that you use should be specially formulated for use with pressure washers.

It’s the weekend and there are so many things to do around the property. On top of that, you need to wash the car. Your pressure washer has been so faithful at a lot of tasks. Then you contemplate if you can use it with car wash soap.

Pressure washing your car is a quick way in which to get the job done. However, you need to be careful and know which products you can use. Read on to find out how you can use car soap with your washer.

car being cleaned at home by pressure washer with soap

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Can I use car wash soap in my pressure washer?

Before you even consider washing your vehicle with a pressure washer, you have to check if your machine is capable of such a task.

Some pressure washers come with a detergent tank. If your washer has this feature, then it’s okay to use it to clean your car. No tank means you’re out of luck.

Car shampoo vs detergent for pressure washers

Usually, car shampoos are out of the question when it comes to using them with your pressure washer. They are specifically made to be applied directly to the surface which can make them incompatible with washers.

The foams and bubbles caused by the shampoo can cause a blockage in the pressure hose or spray head.

However, some shampoos are created with pressure washers in mind. You will need to do your research to find out if the shampoo you are considering buying will be suitable.

Detergent is your better option. That’s because it’s more compatible with pressure washers. Yet, the detergent does need to be diluted.

The dilution process occurs within the detergent tank of the washer.  After that, it is pumped up the pressure washer’s hose and out the spray head.

How does a pressure washer work with the detergent

Pressure washers introduce the detergent in one of two ways: upstream or downstream

An upstream washer has the detergent run through the pump. The downstream option has the detergent brought into the system after the pump.

If you want to go the upstream way and have the detergent enter the pump, that’s fine. Yet, there is one thing you need to be wary of with this system.

Having detergents run through your pump can cause damage. That isn’t to say that there aren’t detergents that you can’t use. Just pay close attention to the type of detergent to ensure that it’s going to be safe for your washer.

Going the downstream way gives you a wider range of detergents and soaps that you can use. For this option, you do need to attach a soap canister to your spray nozzle. The soap is mixed with the water just before it leaves the nozzle.

Cold or hot water

Your choices of detergent are narrowed down even further if your pressure washer only uses cold water. There are some detergents made for cold water and others for hot water

Using the wrong type of soap can cause havoc on your washer over time.

If you can’t tell the difference between the two types of detergent, here is a tip: soaps created for hot water won’t foam so well when placed in cold water. Look at the lather being produced from your pressure washer. If it appears lackluster, then it is hot water detergent.

Related Reading: Is Hot Water Safe for Pressure Washers?

Use the right nozzle

When it comes to using car soap with your washer, consideration needs to be made about the nozzle on your pressure washer. Use the wrong one and the water pressure coming out of the spray head can damage your vehicle’s exterior. Not an ideal situation.

The best nozzle is the 65° Blacktip. This produces the most gentle flow of water and is great for giving your car a great lather.

You could also opt for the 40° tip. This is the second-lowest pressure tip in the nozzle range. Yet it won’t be as effective as the blacktip in coating your car with soap.

The water flow rate

When it comes to cleaning your car, you want a decent amount of water flowing. That is something to factor in regarding whether your particular machine is up to the job.

To save you grief, you will want to have 1.4 to 1.6 GPM coming out of the washer. Anything less than that is fine, but you may find the task taking longer than you envisioned.

How to clean your car with soap using a pressure washer

Having checked the specifications of your washer, you have gone out and bought the correct detergent. Now you are keen to get going with washing your car.

  1. Grab your 25° nozzle and attach it to your washer. This tip will provide you with enough pressure to remove any stuck-on dirt. Give your tires, wheels, and wheel wells a good spray out.
  2. Swap out the nozzle with the 40° tip.  Rinse the entire vehicle. Start from the roof of your car and work your way toward its base.
  3. Change over your nozzle again with the 65° one. Introduce your detergent into your pump (if you are using an upstream option). For the downstream choice, attach the detergent to the spray head. Cover your car with the foam, once more commencing from the roof to the bottom of the car.
  4. Attach the 40⁰ nozzle a final time. Use this to rinse thoroughly rinse off the soap suds.
  5. Wipe your car down using a microfibre cloth

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It’s possible to use car soap with your pressure washer. Yet, you need to determine if you want to go with the upstream model or downstream choice.

The former option requires the use of certain detergents to ensure that your pump internals isn’t damaged. Going the downstream way means attaching the soap to your sprayer but supports a wider range of detergents.

For the task of lathering up your car, use the 65⁰ nozzle when soaping up your car.  It’s made with this task in mind.