What Is PSI Max on a Pressure Washer?

Simpson 3200psi Pressure Washer07

Using PSI Max For Pressure Washer Ratings Can Make Buyers Think They’re Getting More Cleaning Power Than They Really Are

A while back, the pressure washer market started seeing some eye-popping PSI ratings and we noticed a new term attached to those claims. So just what is PSI max?


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What is PSI Max – Defining the Terms

If you’ve been around the power tool industry much, you may notice some brands have 18V tools and others have 20V max tools. On the surface, it sounds like 20V would have more power than 18V. The reality is that 18V is the same as 20V Max.

It can be similarly confusing for pressure washer PSI ratings. First, let’s answer the question, “what is PSI max?” It’s a measurement of the actual maximum pressure the pressure washer produces for an instant. Before we go too far with our pitchforks and torches, it is a relevant number.

By knowing the PSI max, consumers have an idea of the potential risk of property damage or personal injury. We’re big fans of understanding that type of risk.

Different Measurements for Different Manufacturers

The foundation of the problem is that most manufacturers don’t use that measurement. Two of the most common certifications come from PWMA (Pressure Washer Manufacturers’ Association) and CETA (Cleaning Equipment Trade Association). While there are some differences in the two organizations’ testing methods, they both use averages for PSI and GPM that are more representative of what you’ll actually experience when you’re pressure washing.

Another problem with PSI max is that it’s highly inflated compared to the certified PSI ratings from other brands. In some cases, we’ve seen it more than 30% higher than the actual working PSI.

While we’d love to have just one standard to work from, that’s simply not the case. For now, keep your eyes open for PSI max on packaging or product websites. When you see it, look for a clarification of the typical working PSI when you’re comparing pressure washers. A product that looks like the best pressure washer may not actually have the performance you think it does.

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