There are so many variables involved that can make 2 same brand machines and surface cleaners on 2 different trailers work totally different.
The size of supply hose to the pump, size of pressure hose, the amount of 90 degree bends in the system, size of pressure hose on the surface cleaner, running guns and ball valves or just ball valves, good condition swivel vs. worn out swivel, good nozzles vs. old, worn nozzles, etc....
Unless both guys are having the same setup on both trailers with the same tech operating one then the other, chances are the results will be different.
Dimitar, what size of pressure hose are you using?
Wesley, same question?
Both of you, explain your rigs based on this info from up above, maybe the solution is there, maybe not.
With the path of least resistance comes better flow and then better, faster work, maybe too many restrictions in the system on Dimitar's truck?