5 gpm or 8gpm cold water

In the process of researching a pressure washer to buy. It seems that the 5 and 8 gpm (3000 to 3500 psi) units are very close in price. I plan on doing mostly residential. I was looking at the 5.5 gpm 2500 psi for about $1400, adding electric start brings it up to $2200. For a little more I could get the 5 gpm or even an 8gpm. If any of you had to it over would you go straight for the 8gpm? Majority of homes in my area are on city water, not many with well water.

Be careful you don’t eliminate potential residential customers because not all residents will receive 8 gallons per minute. I suggest doing a one minute bucket test at your home to find out how many gallons per minute you receive. In 10 years of experience I have noted that almost all homes get at least 6 gallons per minute. Many do not get 8 gallons per minute. If you bought a pump needing 8 gallons per minute you would need to do bucket test for every customer to be sure you’re not starving your pump.

First, I would recommend a buffer tank for anything over 4gpm. It’s a good idea for any size machine, really, because it allows you to direct the unloader bypass back to the tank and keep cold water running through the pump.

The pressure pro 5.5/2500 is a great little machine- it’s what I use. If you’re handy, you can add a starter kit yourself for a little over $100 (something I plan on doing before spring)

If you’ve got the budget for it, 8gpm is obviously better than 5.5. But understand that it will involve a more serious setup. More water flow means larger buffer tank, means heavier trailer (2 axle), means beefier tow vehicle…

My setup can be towed behind a car, and I can get a very respectable amount of washing done with it. My business is primarily window cleaning, though. If I was pw’ing all day every day, I’d buy a truck and outfit a dual axle trailer with a 8gpm machine and probably a roof cleaning setup, as well.

Electric start kit for $100, that might make my decision easier. Do you have a link for the kit?

I have both and for HW 5gpm is good but 8gpm is great! I would say for both I would get a buffer tank a 50gal will work for the 5gpm but the 8gpm will need at least a 100gal tank. Reason being some homes exterior water flow may very with construction even though city water tends to provide good flow. With that said we do a lot of deck work in the spring and I prefer the 5.6 machines for decks due to the lichen mold in our area it does a great job washing as well but the 8gpm is just a bit faster.

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For your future reference… this is not a truck


I should’ve seen that coming :smirk:

In reality, I’d probably get a van. I’m just not much of a truck guy.

I’ve had this fantasy of buying a used Butler System carpet cleaning van, removing the carpet cleaning equipment, and installing beefy pressure pumps on the PTO mechanism. No noisy engines running inside- just the van’s motor putting ample HP into whatever I want. All chem tanks would be vented externally to avoid rust. It’d be epic…
//odd tangent


There was one on Amazon, but it’s no longer available :confused: