The basic building blocks of power within a pressure washer are PSI (pounds per square inch) and GPM (gallons per minute). Together, they create HP, or horsepower.
The HP of a pressure washer is divided up to produce both the pressure at which the water is released (PSI) and the number of gallons that are released (GPM). For example, a 2.3 HP motor can produce 2.1 GPM at 1600 PSI or it can produce 3.0 GPM at 1100 PSI. Cleaning power is a function of both volume and pressure.
When selecting a pressure, first determine the minimum PSI you need to break the bond between the dirt and surface you are cleaning. The horsepower chart below can help you, or you may wish to contact your Alkota dealer if you need help.