Washing a car with a pressure washer – The Ultimate Guide – How To, The Best One, & More

So you are interested in washing a car with a pressure washer, but you have questions.

You’ve come to the right place my friend. This is the ultimate guide to washing a car with a pressure washer.

We’ll be covering how to use them, which pressure washer is best for the job and your budget, different attachments, safety concerns, and more.

Pressure washers have some great benefits such as speeding up the car washing process, conserving water, making the washing job easier, and minimizing the potential for swirls and scratches in your clear coat.

The main downside of a pressure washer is cost. Some can be had for cheap while others can cost quite a bit.

Washing a car with a pressure washer

The TLDR on our pressure washer recommendation is the best bang-for-the-buck unit is the consumer-grade Karcher K1700. But depending on your budget you may want to step up to the commercial-grade Sun Joe SPX9007-Pro.

You’ll also need to understand how to use your pressure washer properly to prevent damaging your finish and get the most out of it.

You’ll want to understand the spray tips and attachments and which ones you should use as well as which to avoid.

It’s all not as complicated as it sounds so let’s dive right in.

Gas vs electric pressure washer for cars

One of the first decisions you’ll need to make when washing a car with a pressure washer, if you haven’t already, is whether you should go with a gas or electric pressure washer. There are pros and cons to each obviously.

  • Electric pressure washers will generally be more quiet, cheaper, lighter, have adequate pressure, little maintenance, and not require having to deal with refueling.
  • Gas pressure washers will generally be quite loud, more expensive, heavier, have an excess of pressure, regular maintenance, and of course require regular refueling.

These are broad comments and there are always exceptions to every rule but for consumer-grade, affordable pressure washers, this is generally what you can expect.

Based on my research and first-hand experience I can tell you that almost any electric pressure washer is a crap shoot and most likely won’t last more than a season.

Why? Well the consumer-grade electric pressure washer market has been a spiral to the bottom to compete for the lowest price. This means manufacturer’s use cheap components in their products. This, combined with other cost-cutting techniques leads to a product that is not able to work for an extended period of time and is even prone to failure right out of the box.

Some people find electric pressure washers defective in the box.

Others break on first use.

Some last through the first use and break on the second use.

Some even last several uses over the course of a season.

Few will work after being stored for the winter, even after following manufacturer’s instructions for winterizing.

This is even being reported by customers of respectable brand name manufacturer’s.

Due to this it is hard to recommend any consumer-grade electric pressure washer. You would think that a gas pressure washer would be the preferred way to go, but I still suggest an electric pressure washer. This is mostly because you can step up to a commercial-grade electric pressure washer for not much more than the cost of an entry level gas pressure washer.

If you would prefer a gas pressure washer the main consideration you should keep in mind is the ability to turn down the pressure to below 2000 PSI. Some gas pressure washers will even have settings specifically for car washing. You can also purchase special nozzle tips that are sized larger that will lower the pressure output.

Gas Powered
Pressure Washers

Generally More Expensive
More Powerful (Bad)
Requires Regular Maintenance
Requires Refueling

Electric Powered
Pressure Washers

Generally Less Expensive
Less Powerful (Good)
Requires Little Maintenance
No Refueling

Can I use an extension cord with an electric pressure washer?

Another key difference to keep in mind between gas and electric pressure washers is that you’re tethered to an electrical outlet with an electric pressure washer. This seems obvious, which it is, but the issue that isn’t obvious is that you generally shouldn’t use an extension cord with an electric pressure washer.

Electric pressure washers draw a large amount of power and typical extension cords are not up to the task of conducting enough juice. You can purchase a high-quality extension cord that is unusually thick in gauge but you should ensure that the manufacturer states this is possible with your pressure washer and follow any requirements they give. For instance, shorter extension cords are usually suggested however higher gauge cord should allow for longer length. I should point out that these high-quality extension cords are not cheap but a good investment if you need one. Also, be careful to ensure the extension cord connection is not exposed to water for your safety.

Heavy Duty 50 foot / 10 gauge extension cord

Best Consumer-Grade Pressure Washer for Car Detailing - Karcher K1700

If you’re determined to go with a budget electric pressure washer then the Karcher K1700 is the one to get. It currently can be had for a couple bucks LESS than the Sun Joe SPX3000 but it’s a much better built machine.

It has more metal parts used throughout than most of the other cheap pressure washers on the market which adds to its durability and reliability.

It also uses standard size fittings which makes it easy to purchase and use quality foam cannons and other accessories.

The big differentiator however is that it has a 3 year warranty from the manufacturer where they will send you a new unit as replacement. You may have to return the defective unit but that isn’t always the case.

For less than $150 I can whole-heartedly recommend this unit for those on a tight budget. Just know this is still a consumer-grade pressure washer and will not be as well-built as a commercial-grade product. Follow ALL of the manufacturer’s guidelines to ensure that it will last as long as possible and keep you from voiding your warranty.

Karcher K1700

Best Commerical-Grade Pressure Washer for Car Detailing - Sun Joe SPX9007-Pro

If your budget can handle a $300+ expense you may want to consider the Sun Joe SPX9007-Pro. This is quite a bit more cost than the K1700 for similar performance but what you get is a much more industrial-strength product.

While consumer-grade products aren’t designed to take any real abuse and are prone to failure, the Sun Joe SPX9007-Pro is a rugged monster. It’s capable of cranking out 1800 PSI at 1.6 GPM.

It comes with a 34 inch spray wand with trigger. Several spray nozzles including 0°, 15°, 25°, 40°, and a foaming tip. And a 25′ high-pressure hose.

I do recommend that you pick up a good foam cannon for use with this pressure washer to get the most out of it.

There are a couple of downsides to consider before pulling the trigger on this wash however. One downside is the lack of standard-size connectors. This means you’ll need to find an adaptor if you want to use 3rd-party attachments such as foam cannons and spray wands.

Another design choice that helped them cut cost is that this unit has no auto-on/off feature. This adds strain to the electric pump and over an extended period of time could cause premature wear. The solution to this is to simply turn it off when not using it for more than a couple minutes though.

Even though it doesn’t automatically turn off when not spraying, it is extremely rugged and can take plenty of punishment. Plus, this pressure washer is designed for commercial use and not the occasional use that it will receive when used for car washing and detailing.

If you want an electric pressure washer that you don’t have to worry about failing on you and your budget can handle the added expense, this is the way to go.

Sun Joe SPX9007-Pro

Entry-Level Gas-Powered Pressure Washer for Car Detailing - Karcher G2700R

If you’re going to spend over $200 on a pressure washer you may want to consider getting a gas powered one if the downsides of gas-powered pressure washers aren’t an issue for you. This is where you get into entry-level gas-powered pressure washers. It has more power than you’ll need for car washing and detailing but as long as you can dial it back to below 2k PSI and you use a 25° or wider spray tip you should be fine. If you think about the typical gas-powered lawn mower, they last for years and can take a beating when properly cared for.

I prefer electric powered tools in general personally but they aren’t always the best choice. Electric pressure washers typically require less maintenance, are quieter, and are usually lighter which often means they are easier to maneuver around my vehicle.

Unfortunately you have to work around or accept those issues if you decide to use a gas pressure washer. The good news is that this is manageable and the cost of a good gas pressure washer isn’t a deal breaker. Also, gas-powered pressure washers are more powerful which means they are better suited for a wider variety of tasks around your home. The addition of this versatility may offset the additional cost and downsides of a gas pressure washer.

The best entry-level budget gas-powered pressure washer that I’ve found is the gas-powered Karcher G2700R. Karcher is a quality brand and the G2700R is a smoking good deal for an entry-level gas-powered pressure washer.

The downside to this particular pressure washer is that it runs at 2700 PSI which is quite a bit beyond the 2000 PSI that should be the limit for car washing and detailing. To get the pressure of this power washer down to an acceptable level you’ll need to use this set of Size 5 pressure washer nozzles. These nozzles should bring the pressure down to well under 2000 PSI and be ideal for car washing. Unfortunately there isn’t any way to adjust the pressure down built into this washer.

Karcher G2700R

The Less-Than-Ideal Option Everyone Else Suggests - Sun Joe SPX3000 Electric Pressure Washer

The Sun Joe SPX3000 pressure washer is all over the Internet. Like the K1700, it can usually be found for a less than $150 which is astonishing cheap.

Many people praise it as an excellent pressure washer and great alternative to heavy and expensive gas pressure washers.

There are also plenty of people online complaining of failed units. I can’t recommend this pressure washer.

For the money you’re much better off with the Karcher K1700 with its higher build quality and its 3 year warranty.

Sun Joe SPX3000

Previous Recommendation - Karcher K5 Premium Electric Pressure Washer

At approximately twice the price of the Karcher K1700 you can pick up the Karcher K5 Premium. I had previously researched pressure washers and found that while this pressure washer wasn’t super cheap, it didn’t break the bank. It has a little more power than the K1700 but that’s not necessary for car washing and detailing.

This unit was often mentioned by professional and hobbyist detailers as the preferred electric pressure washer in the consumer-grade market.

One big downside this unit has is that it doesn’t use standard fittings which means you are stuck with the attachments that shipped with the unit or you will need to find adapters.

It’s a little nicer than the K1700 but the additional cost combined with the non-standard fittings makes it a less than ideal choice. If you’re going to spend this much you should consider a something else.

Unfortunately the number of complaints online tells me that this is not a reliable choice to recommend anymore. Its probably a safer bet than the consumer-grade Sun Joe, but for this much money I don’t think it’s worth the gamble. Especially when you can pick up the K1700 for much less.

Karcher K5 Premium

Best cost-is-no-object pressure washer for detailing cars - Kranzle K1122TST

For those that refuse to compromise, there are always shining exceptions, and the Kranzle K1122TST is one. While most consumer-grade electric pressure washers are short-lived, this pressure washer is built like a tank. Unlike all the other pressure washers mentioned in this article, this is a commercial-grade product. Because of this, it’s not going to be in the same ballpark price-wise. It will seriously lighten your wallet but you get what you pay for.

Because of the extensive use of metal in the construction, this isn’t a light-weight washer, but it is still very maneuverable. At 80 pounds it is hefty but the large integrated wheels make it easy to move around and position where it’s most convenient.

The pump is designed to be laid down when in use. This is ideal for the design of the pump and keeps the unit secure in place when in use.

It incorporates a hose reel to keep things tidy and the winding handle folds away when you’re done. Additionally, the hose that is included is wire-braided for incredible durability and is a lengthy 50 feet long. The power cable is another 35 feet in length giving you a total of 85 feet of reach, not including spray distance.

It includes a quality gun attachment as well as 2 lance attachments. One lance is a dirt blaster and the other is a variably adjustable tip.

The pump is capable of outputting 1400 PSI at 2.1 gallons per minute which is more than adequate for car washing. Another nice feature is the automatic start/stop function of the motor which helps with efficiency and extends the life of the hardware, but also keeps things quiet when not in use.

This pro-caliber electric pressure washer is going to exceed $1k. If you have the income to easily afford this pressure washer I highly recommend it. You get all of the benefits of electric pressure washers and get rock-solid reliability. For us mere mortals however, this is a luxury item and we’re best suited with something more affordable.

Kranzle K1122TST

Is it safe to wash a car with a pressure washer?

It is safe provided you use the proper tip, don’t exceed 2000 PSI, and use care with where you’re spraying. A good rule is if you can handle spraying your hand with it and it is tolerable then your finish should be fine. Be careful though. You can seriously hurt yourself with a high-pressure washer and/or a focused tip.

Always be careful what you’re spraying. Some bits on your car or truck can be more fragile than others. If the pressure you’re using is on the high side you may find that while the finish doesn’t get damaged from the pressure, some other bits and pieces may not be able to take the stress.

If you have a convertible top or frameless windows you should be especially careful with pressure around seals. The high pressure of your pressure washer can force water past some of these seals in some cases and spray water into the cabin of your car or truck.

If you’re unfamiliar with what a frameless window is you can easily check. If you open your door with the window in the fully closed position and the glass edge is exposed when the door is open, you have a frameless window. Framed windows slide into a metal frame that is permanently fixed to the door frame.

The tip or attachment you use is also very important. Especially if you can’t adjust the pressure of your washer via a setting on the unit. The nozzle tips you use can adjust the pressure coming out of your washer. You want to use a tip that creates a wide spread so as not to concentrate all of the pressure in one spot on your car or truck. Tips that are 25° or wider are recommended. There are also different sizes of nozzle. Larger size nozzles will allow for more flow at a lower pressure. If you need to lower the pressure of your power washer with a different size tip you can use this pressure washer nozzle chart at PowerWash.com to find the tip that will best work for your needs.

Another important safety tip is to be sure and not kick up dirt, rocks, or other debris around your vehicle. Pay attention to the area you plan to park your car or truck when washing it. Be sure there is not a lot of gravel or other debris around. When spraying your vehicle avoid spraying the ground near it to prevent debris from flying up and nicking or chipping the finish.

How to - Washing a car with a pressure washer

At the beginning we mentioned that pressure washers speed up car washing, make car washing easier, and can help reduce the potential for swirls and scratches on your paint finish. This is only true however if you are well prepared and know how to use your pressure washer properly.

Here are the steps to follow when washing a car with a pressure washer to ensure you’re using it properly:

  • Rinse off your vehicle with a minimum of at 25° tip
  • Use a foam canon and a Ph neutral car wash shampoo to coat your car or truck in a thick layer of suds
  • Allow the suds to sit for a few minutes and break down the dirt and debris on the finish

If your vehicle is particularly dirty:

  • Use a quality microfiber wash mitt to wipe down all of the exterior surfaces
  • Re-foam occasionally if necessary
  • Rinse with a minimum 25° tip

If your vehicle is only lightly dirty:

  • Rinse with a minimum 25° tip – the dirt should be loosened enough from the soap to be blasted away by the pressure washer
  • Dry your car or truck with a quality microfiber towel or air dryer
For more information on best practices when washing your car you should read our article “Best Way To Wash A Car Without Scratching The Paint“.

Why use a foam cannon

Your pressure washer may come with a soap dispenser or it may not. Whether it does or not, most people will recommend using a quality foam cannon attachment. This may seem unnecessary but there is a good reason for this. A good foam cannon is going to do a better job of laying down a thick coating of foamy suds on the surface of your vehicle.

A thick coating of foam will increase the amount of time that the soap can work at loosening the dirt and road grime from the surface of your car or truck. A thin, watery coating of soap with fade away rather quickly and limit the time the soap can do its work. If the soap can do the work of loosening grit and dirt it will easily be blasted away when rinsing with your pressure washer.

If you have to use something to physically touch the surface to wash off the dirt and grit you run the risk of lightly scratching the clear coat of your finish. The dirtier your car or truck the more likely soap foam won’t be able to do the job alone. Even if your vehicle is extremely dirty, reducing the amount of dirt and grit that you have to physically wipe away helps reduce the opportunity for swirls and scratches to appear in your clear coat.

MTM Hydro Foam Cannon Kit

Do you need a special soap for a foam cannon

Yes and no. You should use a Ph neutral car shampoo but you don’t need a soap specifically designed for foam cannons. A Ph neutral car shampoo should be used whether you’re hand washing your car or using a foam cannon. The reason for using a Ph neutral car shampoo is because this will loosen dirt and grit without stripping away wax or paint sealant.

You shouldn’t use dish washing soap or similar products unless you want to strip away some of your wax or paint sealant. You can’t count on it stripping it all off and leaving your clear coat completely unprotected but it will wear it away far more than a quality Ph neutral car shampoo which should leave it intact.

Chemical Guys Honeydew Snow Foam

Helpful Links

Conclusion - Washing a car with a pressure washer

The state of consumer-grade electric pressure washers today is pretty sad but the Karcher K1700 is a standout in a disappointing crowd. It should be reasonably reliable and if you have trouble Karcher will replace the entire unit for 3 years.

For a little more peace of mind you can step up to the Sun Joe SPX9007-Pro commercial-grade pressure washer. It’s built like a tank and should last as long as you need as long as it is properly cared for. It does have the downside of non-standard connections and no auto-on/off but it is still an excellent value despite these minor inconveniences.

For those of you with extremely deep pockets, you may want to consider the Kranzle K1122TST. It is orders of magnitude more expensive but you really can’t find a power washer that is any better than this one for car washing and detailing.

Washing a car with a pressure washer is pretty straight-forward but you do need to follow the safety tips suggested. In short, make sure your pressure is less than 2000 PSI, you use nozzles wider than 25°, and you take care not to kick up rocks and debris from the ground that could damage your vehicle.

A good quality foam cannon and a Ph neutral car shampoo round out the recommendations. This will protect your wax or paint sealant while maximizing the cleaning power of the shampoo and reducing opportunities that could cause swirls and scratches in your clear coat.

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