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How to Choose a Pressure Washer: A Complete Guide

How to Choose a Pressure Washer: A Complete Guide

A pressure washer can be a valuable tool for maintaining the beauty and integrity of your home or your car. With the appropriate pressure washer, you can keep your car spotless, your walkways moss-free, and your house siding looking great. It can also do wonders for your driveway.

But how do you choose the best pressure washer for your needs? How powerful do you need a pressure washer to be? Should you go with a gas pressure washer or an electric one? These inquiries and more will be answered in this guide. Read on to learn all you need to know about choosing the perfect pressure washer for your needs.

How to Choose a Pressure Washer: Measurements to Consider

What should you look for in terms of power when looking at pressure washers? How much pressure is enough, and how much is too much? How do you tell the difference? As with other pieces of equipment, you can objectively evaluate pressure washers by specific measurements of their performance.

When rating pressure washers, the first thing you need to realize is that there are three different measurements to consider. Once you wrap your head around these terms and what they stand for, you will be able to choose your most suitable pressure washer.

  • PSI (pounds per square inch)
  • GPM (gallons per minute)
  • CU (cleaning units)

When looking at the pressure of water that a pressure washer can create, you need to look at how many pounds of pressure it can produce for every square inch of water (PSI). When looking at the amount of water that a pressure washer can use, you need to consider how many gallons of water it uses every minute (GPM).

Finally, you need to consider the cleaning units a pressure washer can create. CUs are used to rate the combined value of the PSI and the GPM. Think of it this way: a pressure washer can have all the PSI in the world and still clean poorly if the GPM is not equal to what the PSI can handle.

Choose Your Pressure Washer GPM

What is a good rating to look for in terms of gallons per minute? Do you need a high number of GPM or a low number? Luckily for you, there is a standard GPM you can search for. However, the best way to understand GPM is always going to be in terms of what it does when combined with the pressure washer unit’s PSI.

The GPM rating you will typically see on pressure washers is going to be between one and four (gallons). This will accommodate most applications for home or residential use. You will also see this rating applied to both electric and gas pressure washers. You will not need a higher GPM rating unless you have heavy-duty commercial requirements.

This GPM rating will also accommodate a variance of PSI. With a one to four GPM rating, you can expect to see pressure washers supporting a PSI between 500 and 4,200. This gives you a choice of pressure washers in the light to medium range.

Choose Your Pressure Washer Power Range

It is helpful to think of pressure washers in three power categories. These categories relate mostly to the level of cleaning power you want the pressure washer to achieve. Within these categories, you will find a range of GPM, PSI, and CU that correspond to each level.

The three levels of cleaning pressure washers can achieve are:

  • Light
  • Medium
  • Heavy

It is easy to decide what power category you need based on the cleaning you plan to do. If you only need to use your pressure washer for residential use, you can rely on a light pressure washer. Medium pressure washers will accommodate folks who use pressure washers more often, for larger jobs or for occasional commercial jobs. 

Typically, only commercial or professional level users will need a pressure washer that can accommodate heavy-duty cleaning. These pressure washers are also made to last a long time, even with constant everyday use.

Pressure Washer Power Categories Explained

Here are the ranges within the three categories of pressure washers:

  • Light pressure washers have a PSI ranging from 500 to 4,000 with a GPM of one to four for a total CU of 1,560 to 16,000
  • Medium pressure washers have a PSI ranging from 1,000 to 4,200 with a GPM of one to four for a total CU of 2,400 to 16,800
  • Heavy-duty pressure washers have a PSI ranging from 1,000 to 7,000 with a GPM of one to 10 for a total CU of 2,500 to 30,000.

Calculate the CU

As you can see, there is some overlap in the ranges of the different measurements. The medium and heavy-duty categories have the same baseline for the PSI, and there is only minimal change in the range of PSI between light and medium pressure washers. 

Similarly, the range of GPM remains the same for light and medium pressure washers. And while the range of GPM extends much higher for heavy-duty pressure washers, its baseline remains the same for all three.

In many ways, the CU tells the best overall story when evaluating pressure washers, which becomes clear when you realize how you calculate this measurement. You simply multiply the PSI by the GPM, and that gives you the CU. So if you have a PSI of 700 with a GPM of 2, your CU would be 1,400.

That is why the CU tends to have a broader range, especially between medium and heavy-duty pressure washers. There are many variables between the PSI and the GPM that can affect a pressure washer’s CU.

Choose Between an Electric or Gas-Powered Pressure Washer

An important question to answer when choosing a pressure washer is whether you should buy an electric pressure washer or a gas-powered pressure washer. This choice is at least as important as choosing the rating above when deciding on the best pressure washer for your needs.

Here is the bottom line: You can get good pressure washers in either the electric or gas-powered category that will accommodate almost any residential cleaning jobs you may have. Because of this, your decision comes down to your own individual needs. The features and specifications you want will help set your priorities and make a choice.

In general, think of your needs in terms of these categories:

  • The cleaning you will generally need your pressure washer for
  • How far away from a power source you will need your pressure washer to be
  • Your ability to move heavy equipment
  • How often you will typically need to use your pressure washer

Electric Pressure Washers

Electric pressure washers come with a compelling list of benefits. You can actually get an electric pressure washer that delivers four GPM with 5,000 PSI. Most electric washers are going to be well within the light to a medium level, making them more than adequate for residential use while also being able to tackle some heavier work.

One of the biggest benefits of an electric pressure washer is the noise level. They can deliver the power without the noise of a gas engine. They are generally cheaper, and they do not require gas, so their maintenance and upkeep costs are less than those of gas-powered pressure washers. 

Electric pressure washers do have their downsides, though. 

  • Electric pressure washers are not as limitlessly portable as gas-powered pressure washers because the power cords must be plugged into a power source.
  • It is not recommended that you use an electric pressure washer with an extension cord.
  • As a general rule, electric pressure washers do not last as long as their gas-powered counterparts. 

If you have a lot of property, the length your pressure-washer can reach is something you will want to consider. Also, if you plan on pulling your pressure washer out once a year for spring cleaning, this may be okay. But if you plan to use it with regularity, its durability could make a real difference in your decision.

Gas-Powered Pressure Washers

Gas pressure washers, on the other hand, tend to have the following advantages.

  • They are more durable and last longer than electric pressure washers.
  • They are fully portable and do not have to be plugged into an outlet via a cord.
  • They are able to reach the highest levels of PSI and GPM

The strong durability of gas-powered pressure washers makes them more ideal for someone using a pressure washer at a professional or even semi-professional level. Also, because the highest levels of PSI at GPM are only achievable gas-powered units, they are the only way to go if you need to do heavy-duty, commercial cleaning.

One major drawback to using gas pressure washers is that they are noisy. There is simply no way around that. Additionally, while they are more portable, they are heavier because they hold a motor and gas tank. They require the extra costs of gas or a specialized gas mixture to run and the occasional oil change and engine maintenance.

If you are on the fence about this, you may consider that if you use the unit regularly, maintenance may cost you less in the long run than having to buy a new unit altogether. As you consider which is best for you, you will find that the differences may lie in some of the following factors:

  • Budget
  • Ease of use
  • Portability
  • Frequency of use
  • Depth of cleaning


It is perfectly natural to make an equipment purchase based on budget. In this case, you can get a good pressure washer even when you decide to choose a cheaper version. Even considering all of the things that may make one type of unit better or more powerful than another, many affordable units are just as effective for certain jobs. 

If you are looking for a low-priced pressure washer, you will likely be looking for an electric unit. Gas-powered pressure washers can start at around $400 and easily cost well over one thousand dollars. Alternatively, electric pressure washers tend to cost between $80 and $300. 

Of course, there are also electric pressure washers comparable in price and performance to gas-powered pressure washers. If the price is not an issue, how do you choose between electric and gas-powered pressure washers?

Ease of Use

If your biggest priority is being able to use the machine without a lot of hassle, then the electric pressure washer is definitely the unit for you. They are simple to get in and out of the garage, setup, and turn on.

A gas-powered unit has more steps to go through and more to take care of. Also, the gas-powered unit is heavier, which means that for most residential areas and owners, it could take more effort to move it along walkways and around landscaped areas.


As was mentioned before, both units can be moved. The above section looked at how easily they can be moved. Now you need to consider how far you need your pressure washer to move. If your home has regular availability of outside plugs, having an electric pressure washer will probably be manageable.

However, if electrical outlets are hard to come by around the house, or you have a lot of property that you need to access with your unit, having a gas-powered pressure washer is a must. The electric unit’s ease of use has no appeal when you cannot use it because there is no access to electricity.

Frequency of Use

This factor can actually go both ways. It depends on how you prioritize the issues that arise when using your pressure washer.

  • I use it a lot, so I want to be able to use it easily, or
  • I use it a lot, so I want it to withstand my abuse for a long period of time

Sadly, in this situation, you are not likely to have one pressure washer that can do both. Being easier to use, the electric pressure washer is going to appeal to the person who wants less hassle over the course of multiple interactions with any given tool. This person does not mind replacing it more often for the sake of convenience.

If it really irks you to have to replace a piece of equipment more often than you would otherwise have to if you had bought a different version, then the gas-powered pressure washer is probably going to be your thing. They have fewer plastic parts, so gas pressure washers tend to be more durable.

Depth of Cleaning

Finally, there is the issue of results in terms of cleaning. Does one type of unit clean more deeply than the other? Keep in mind that within the light to medium level of cleaning (which is the level of cleaning that most homeowners will need from a pressure washer), both types of units are comparable.

Still, there may be a case for having a gas-powered pressure washer that can reach higher levels of PSI and GPM. If you have acquired an older home that needs a heavy-duty cleaning. A gas-powered unit might be the way to go.

However, you may have a newer home that looks great, and you simply want to maintain it. You can do so well with an electric unit during an annual cleaning. You can also use the same electric unit to detail out your car. In this case, either unit is appropriate.

Gas or Electric Pressure Washer for Home Use

Once again, this choice comes down to how you plan to use your pressure washer. In most cases, both types of units will be able to do what you need to get done around your home, whether it is pressure washing siding, windows, or walkways.

Gas or Electric Pressure Washer for Car Detailing

Each type of power washer is capable of car detailing without harming your car. Keep in mind that in order to detail your car with a pressure washer safely, you need to use a lower setting on whichever type of pressure washer you choose. This way, the strong spray will not damage the paint.

When detailing your car, using the most powerful unit can be a detriment. You do not want to strip off the paint while trying to get that nasty bug mess off of the hood. You need to have a unit that can operate at around 1,200 to 1,900 PSI with only around one and ½ GPM.

That said, if detailing your car is one of the main things or even the only thing you will do with your pressure washer, an electric unit is probably the best way to go. The levels of cleaning that you need are easily achievable with an electric unit, and you do not have to worry about a gas-powered unit producing too much power.

Ease-of-use for this kind of project cannot be beaten. With an electric unit, you can plug it in inside your garage and wheel it to the car or even have it at the garage door. Another big advantage with an electric unit is that you do not have to worry about carbon monoxide poisoning if it sits in your garage during use.

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