If you want a unit with more psi consider a mobile gas pressure power washer. They are designed for cleaning large areas in remote surroundings where no electricity is available. High power washers usually have higher performance ratings, faster cleaning times, and industrial parts and attachments. They offer a convenience of independency and easy maneuverability. When buying this model make sure it is equipped with: pump with ceramic plungers and stainless steel valves, chemical injection, 4 different size nozzles, and good pneumatic tires. Note: if you expect the fuel to sit in the tank for more then 4 weeks, make sure to add a fuel stabilizer to prevent from varnish deposits from polluting the carburetor. Gas pressure power washers come in the variety of different engines, but among the most popular once are HONDA and Briggs & Stratton pressure washer engines.