Naturally, the typical specs are:
a) the hp rating of the engine b) the gpm c) the psi
So my main question is - are these numbers fudged, or have a wide accuracy range?
What is the minumum rating (in terms of gpm and /or psi) that make it worth while to actually buy one of these things?
The range I see are from 2 to 4 GPM, and roughly 2000 to 4000 psi. Engine HP from 6 to 13.
Your answer should not include "it depends on what you want to wash".
I want to know if a washer that does 2 gpm @ 2000 psi has only half the "cleaning power" as one that can do 4 gpm at 4000 psi (ie does the cleaning power scale linearly with these numbers, or geometrically or exponentially).