I'd be looking for a 8gpm unit. These are the best of both worlds. If you have a 13HP or larger unit upgrade the pump to an UDOR. These pumps are priced right and have never let me down. In fact I have one on the big truck with 3 seasons on it. By my calculations it has pumped nearly 1 000 000 gallons. Only thing which went wrong was a bad intake valve. (broken spring) Yes there are a million ways to go but having the option of GPM with pressure is allways nice.

DAFF MOBILE WASH
WINDSOR, ONTARIO CANADA
DAFFMOBILEWASH@AOL.COM