Wash Wisely

Reviews and General Information
on Pressure Washers

Pressure Washer Power Ratings and Sizing

Before I discovered the wonderful world of power tools, I was doing all the repairs and remodeling around my house manually. It not only took me forever to get stuff done, but in some places my work left much to be desired.

Now I have some power tools at my disposal I can get a lot more work done in a shorter time span, and the quality of work is superb. I decided to apply the same recipe when it came to cleaning my house and backyard which is one reason why I decided to buy a pressure washer.

I cannot tell you how useful they are! Well, actually I can because that’s why you see this website before you today. In the beginning, stumbling across all those numbers and strange acronyms that seemingly don’t mean anything can be pretty confusing but don’t worry, I will explain everything.

Power Ratings and Sizing

Unlike the power of your car which is expressed through in the number of horsepower its engine is able to produce, pressure washer power is expressed in pounds per square inch (or PSI). Before I get into that, I have to address one thing to avoid confusion.

In most of my reviews I have discussed engines built into pressure washers, and I have mentioned how much horsepower they are able to produce. Of course, as is the case with any internal combustion engine it produces horsepower. Except when we are talking about electric pressure washers, where power is expressed in amps.

When you hear the words “pressure washer power” it is always used to refer to the cleaning power of the unit in question. Horsepower may be directly related to this but not necessarily, and isn’t a terribly good indicator of true cleaning power.

As previously mentioned, the power of every pressure washer is expressed in pounds per square inch (PSI) and gallons per minute (GPM). PSI refers to the amount of pressure applied by a water jet shooting out of the spray to the surface you are cleaning. GPM on the other hand, refers to water flow or the volume of water delivered over a certain period of time (in this case 60 seconds).

Electric Power Washers

Smaller PSI numbers ranging from 1300 to 1800 PSI, and 1.5 GPM flow rate are usually reserved for electric pressure washers. These washers are normally characterized by small weight and dimensions, ease of use and maintenance oh, and lower price.

The kind of power they deliver is suitable for small-scale cleaning tasks like window or car washing, patio cleaning, and so on. Electric pressure washers are also ideal for indoor use because they (as opposed to gas-powered units) don’t produce any fumes which are toxic. Also, they are small enough not to get in your way while working which is a big plus.

Gas Power Washers

Pressures ranging from 2000 to 3000 PSI are generally delivered by gas-powered pressure washers. Gas-powered engines can deliver a lot more power than the small induction motors found inside electric pressure washers. More power means higher water pressure coming out of the spray wand.

These units are not suitable for indoor use not just because of the fumes, but because they can be quite bulky which can do more damage than good. However, gas-powered pressure washers are ideal for heavy-duty outdoor jobs such as cleaning decks, walkways, pavements, brick, siding and patio furniture.

Industrial pressure washers are the most powerful, and can deliver anywhere between 3000 and 4000 PSI or even 7000 PSI in some cases. These are suitable for the toughest cleaning jobs such as washing oil, grease, graffiti and stripping paint.

The use of detergents is also quite common with all types of pressure washers, especially when you need that extra bit of cleaning power. You have to be careful though. You see, you cannot use just any detergent you come across as it will damage the pump and the engine. Every pressure washer has an instruction manual that lets you know what kind of detergent you can use.


Next time you read about pressure washer power and come across all those PSI and GPM numbers, you will know exactly what they are talking about. Not so complicated now, is it? I am glad I was able to help (which hopefully I have).

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