What is PSI Max on a Pressure Washer?

using a pressure washer on vinyl siding

Using PSI Max on Pressure Washer Ratings Makes Buyers Think They’re Getting More Cleaning Power Than They Really Are

When the pressure washer industry started seeing some outrageously large PSI pressure ratings, they (and we) noticed a new term at the same time. What new terminology backed up those amazingly high PSI numbers? Well, these pressure washers had a “PSI Max” rating. What on earth is PSI max on a pressure washer? Read on.

PSI Max is All About Marketing

If you know anything about power tools, you know about the difference (or lack of) between 18V vs 20V Max tools. Some brands call themselves 18V tools while others go by 20V Max. You might, aside from experience, believe 20V simply must have more power than 18V. The truth? Both 18V and 20V Max tools have the same voltage .

So what has that got to do with pressure washers and PSI Max? Everything.

Pressure washers are all about two things: pressure and water flow. That equates to PSI (pressure) and GPM (water flow). PSI stands for pounds per square inch and GPM stands for gallons per minute.

When it comes to pressure washer PSI ratings, manufacturers want nice big numbers. What PSI max does is let pressure washers carry that higher number—but not in a meaningful way.

PSI Max, as a measurement, measures the actual maximum pressure a pressure washer produces for an instant. Now, before we gather the lynch mob and go after manufacturers who still use this term, let;’s try and at least understand its relevance—however small it may be.

What PSI Max Tells You About Pressure Washers

By knowing the PSI max. number, a consumer understands the potential maximum peak pressure at any instant in time. That equates to the potential damage (to property or person) the pressure washer might do in an instant. Understanding risk? We can get on board with that. We just don’t want to go overboard.

The crux of the matter has to do with the fact that most manufacturers simply don’t use PSI Max. As a measure of understanding cleaning power, it doesn’t really help.

How the Rest of the Pressure Washer Industry Measures PSI

Two of the most well-known and most-used certifications come from the PWMA (Pressure Washer Manufacturers’ Association) and CETA (Cleaning Equipment Trade Association).

Those two organizations have some differences in how they test and certify products. Both average PSI and GPM to get numbers that more accurately represent what you might experience when using the tool for its intended purpose…pressure washing.

Final Thoughts

One final problem with PSI max includes the numbers themselves. They’re highly inflated when compared to the certified PSI ratings from other brands. How inflated? We’ve seen it as much as 30% or higher than the actual working PSI numbers. That’s enough to make consumers think that a $199 pressure washer can compete with a product costing 4X as much.

And that’s the key issue for manufacturers. They don’t want industry confusion—particularly if it leads to false impressions and bad comparisons.

While one standard would be nice, we may not get that just yet. Watch out for anything stating “PSI max” on packaging or product websites. If and when you do see it, look for a clarification of the typical working PSI when you’re comparing pressure washers.

Related articles

Best Electric Pressure Washer Reviews for 2023

From cleaning the driveway to making sure your vinyl siding is mold-free, you want the best electric pressure washer (your) money can buy. Having used so many of these personally, we assembled a list of our favorites. Separated by application and training, we created this list for a variety of use scenarios and needs. If […]

Toro Super Recycler Self-Propelled Lawnmower

Toro Introduces New Technology with Super Recycler Series Toro is synonymous with gas- and battery-powered lawnmowers, so it’s not surprising that we’re looking at another one, the Toro Super Recycler Self-Propelled Lawn Mower. Our objective: To explore what this 21-inch gas-fueled grass chopper can accomplish for the homeowner. The Toro Super Recycler Design Features The […]

Greenworks Commercial Battery-Powered 20-inch Chainsaw

Greenworks 82V 20-inch Chainsaw Helps Power Through Jobs The Greenworks Commercial 82V battery-powered chainsaw stands within a select group of manufacturers (see the DeWalt 60V chainsaw and the Stihl MSA 200 C) releasing 20-inch models. All of them have the power to tackle large properties—we’re talking farm and ranch class here. Greenworks Commercials model produced […]

Notify of

Inline Feedbacks
View all comments
Would love your thoughts, please comment.x