On Sun, 12 Jul 2009 09:09:11 -0400, Some Guy wrote:

....

How about this. I want to use it to wash my windows one day and carve
granite statuary another day. Does that help?

I hope you are not planning to use the same tools for both.


I'm asking if the GPM and PSI numbers (and engine HP numbers) can be
trusted from one make/model to the next.

Not very. They both likely will have inflated their numbers.
This kind of misrepresentation is most common on consumer grade tools
than professional or industrial.


I'm asking what are the minimum GPM, PSI and engine HP numbers that make
it worth while to buy and use these things.

It depends on what you want to use it on. I would go a little
further and suggest that not only what you want to use it on but also
what make and model tool, not just the GPM and PSI.

Sort of like asking what the Towing capacity and the fuel tank
capacity is needed for for a car and not telling us what you want to
do with that car. We might guess you want to tow a boat, but that
could be a 40 foot power boat or a 10 foot row boat.

Would you tell you doctor you have a pain, and you want to
know what to do about it and refuse to tell him where the pain is, or
when you feel it?