Real difference between 4 and 5 GPM?

[Peak Mobile Wash 14]

I am sure some of you have seen my other thread looking for a compact trailer rig. Well heres my new question. What is the real difference between 4 and 5 GPM? I mostly do residential work now but would like to get into more commercial work (flatwork, store fronts, construction cleanup). I have my machine choices narrowed down but wanted some advice from the vets around here as to how much more I will really get done with an extra gallon per minute. I am ok with cleaning things a little slower at this point, just as long as I can still do a quality job, will this be possible with 4GPM?

Thanks, Happy new year

[Jeff 232]

It really makes a HUGE difference, please spend the extra , because you will make it back in time saved 4GPM vs 5.5 is a world of difference. 5 gpm or even better a 5.5 will push a surface cleaner A LOT better, it will rinse A LOT Faster

I used many 4gpm's for a long time and I kick myself in the butt for all the time & money I wasted using 4gpm

Good luck to you

Jeff

[Lightning Gene 66]

What Jeff said ! Go aleast 5.5

[plainpainter 217]

I like 4gpm machines - if money is really tight - you can certainly get by with a 4gmp machine. Before I ever came to this site - people thought of 4gpm machines to be extravagently huge. And were often cited as for professional purposes. I have a 5.5gpm cold water machine from Bob - and I think it cooks - but then you have guys here who think 8-10gpm machines are where it's at. Who knows - perhaps if you're going to condo buildings and such. But you can get a good amount work done in a residential setting with a 4gpm machine - unless you really need to do lots of surface cleaning - there you really need a bigger machine. But for wood deck restorations and cleaning smaller ranch type homes - 4gpms' all the way.

[DAVID V 22]

I had a 4 gmp for 1 1/2 yrs and now have had a 5.5

for about 6 mos. It's the best thing I did.

You said you're looking into comm. work. You can push

a bigger surface cleaner, that alone will pay for itself.

[Peak Mobile Wash 14]

My biggest sticking point on a 5GPM+ machine is the amount of water i will have to carry. I do not have a big truck and can only pull arund 4500 pounds so I cannot have a big water tank. I won't want a machine that is pumping 5+GPM and is going to suck my tank dry in a matter of minutes. If I had a truck that could carry big water none of this will be an issue but I have to work with what I've got and this truck is all I have currently.

[Littlefield 65]

You will have your tank set up with a float valve and pull from customers water supply anyway, right? If your truck is holding you back from getting the right equipment to do commercial work, the solution is one of two choices: Upgrade your truck, or don't bother getting into commercial work. Stick with what works for you, but don't ignore good advice from people that have made the mistakes already and regretted it. I've never heard a single person on here complaining about their 5gpm being "too powerful, or too fast."

If you're doing resi, go ahead with a 4 gpm now and use it as a second or a backup next year, otherwise save your pennies for the 5 or 8 gpm.

[Jeff 232]

My biggest sticking point on a 5GPM+ machine is the amount of water i will have to carry. I do not have a big truck and can only pull arund 4500 pounds so I cannot have a big water tank. I won't want a machine that is pumping 5+GPM and is going to suck my tank dry in a matter of minutes. If I had a truck that could carry big water none of this will be an issue but I have to work with what I've got and this truck is all I have currently.

You really should not have to transport water often. You have the tank as a buffer, most areas have 5+ gpm coming out of hose bib of homes & biz, some dont, but you roll up start filling tank and set up and you are ready to go

Please Please research this, if you can only afford 4gpm, fine it will do the work. BUT 5.5gpm I have no problem keeping it supplied with water and when Im done I roll down the road with very little water in the tank

I have 8 gpm machines also, 5.5 is great on house washing. If a house takes 2 hours to clean with a 4gpm, you will knock off a lot of time with 5.5gpm Save at least an 1/2 hr or MORE per house. Add it up 100 house save 1/2 hr thats 50 hours saved you could do another 25-30 homes with the time saved. think of it as 50 hours saved at an average rate of $100 an hour, thats $5K, pays for that machine in no time

Dont worry about carrying a lot of water, you will not need to in 99% of jobs

[PPC 37]

If u are really looking in to commercial work you should spend the extra $ and get the 8gm I got one and its the best thing I ever did I know Jeff likes his and i also know a few other people thet have one and they love it I went from 4gpm to 5.5 to a 8 I still have the 5.5

[David O'Connell Jr. 14]

One of our machines was a 5.5 and we went to an 8.5. I wish that we switched sooner. Night and day. NO COMPARRISION.

You'll need a float tank with what ever you choose. That being said, why not go with the biggest pump possible? (Budget allowing)

We rarely drive with water, so the weight problem doesn't really apply to us. (We have an NPR)

Driving with water is a pain and causes a lot of wear and tear if not necessary. Here you can't qualify with a machine for anything less than 6 gpm for a lot of bids. Keep what you have and get that 8gpm.

[MMI Enterprises 289]

As most are saying..a 5gpm is never said to be too fast. In other words you could take that to mean it just isn't and you'll want more. Get at least a 6 for commercial flat work when the jobs or over a few thousand feet in size. By all means ya have to have heat with any choice for flat work. 5gpm is considered a do all middle of the road machine. Feels plenty if not too much for resi house work or deck work but weak when staring at 20k feet or plenty of rinsing. GPM is what moves water and debri and the more of it you have the wider fan you can get away with using too. Lots of rinse work is done with bigger machines around here to where I hardly consider it pressure washing really as the fellas hold their wand tips feet away from surface rather than inches. To be able to do this on fairly clean maintenance accounts ya need about a 6 I would say. I can't do it with my 5. Am just too anal about it as I know I am not quite getting enough the dirt. Have to be right there up close with a 5. To digress a tad though my 5 pushes a surfacer fine. A 6 or 8 would do that much better due to shear power hitting surface. If it turns fast enough to not outwalk your pace then yer good to go.

As you go up in gpm though I imagine you have to allow that some parts..maybe hosing, burner, etc. is going to be more robust, larger, or cost more. With an 8 I assume there will be plenty more locations that just can't supply it with their onsite supply without you having tank to feed it. Doubt a small float tank could make much difference less you let go of trigger regular to let the supply catch up. I still have no full size tank and that is why I don't move up in size. Never heard a 6 being overly limited to being tank supplied though. Just depends on the volume available at the location really and whether they up to snuff. More and more these days they putting these hose bibs on that limit flow in the commercial jobs that would other wise be small enough to do without a tank. No tank leaves door open to complications or being limited.

[John Orr 206]

I do mostly residential and used a 4 gpm/3500 Home Depot machine for a few years. It can and will work just fine for residential. When the pump finally went (1500 - roughly - hours of use, so I wouldn't let the direct drive vs. belt drive argument influence my decision) I replaced it with a 5.5 gpm gear drive pump. Though rated at 3000 psi, with a 13 hp engine, I get about 2600 psi. Even with lower pressure, the 5.5 cleans faster (I downstream mostly) and runs a surface cleaner much better than before. Having said all that, the 5.5 is now the back-up to my 8 gpm/3000psi rig. Now we're talking! lol

My recommendation? Get the most gpm's you can. I recall there was a dealer somewhere planning on offering something like my back-up. As far as water, most hose-bibs will put out at least 5 gpms. I usually only carry 50 or so gallons to a job, filling as I go, and usually - even at 8 gpm - have no problem keeping-up and even exceeding usage.

[Peak Mobile Wash 14]

Thanks for all the great advice everyone. I am going to go with at least 5GPM for now. I did see a machine that pumps 5.2 I think that is the front runner.

[Beth n Rod 1,279]

If you can go with the 5 now, I would say do it. It's a huge difference. GPM's are important.

Beth

[DAVID V 22]

Something else to consider is your hose. I had single wire b4, now I have double wire.

I find the weight of double a pain.

Also not as flexible, you might have to replace it sooner, but it will help you when you get as old as me. LOL

[PressurePros 248]

This is just going to be redundant but don't twice about going to the 5.6 if your budget allows. If your marketing is in place to do so I'll venture that you will be able to perform an extra job per week just going with that extra gpm. That will more than compensate the added the expense in no time. I'm going to dual gun 12 gpm machines this year. I rented a couple of 8 gpm machines for a flat work job we did this year and was blown away by the difference. GPM is king.

[John Orr 206]

Something else to consider is your hose. I had single wire b4, now I have double wire.

I find the weight of double a pain.

Also not as flexible, you might have to replace it sooner, but it will help you when you get as old as me. LOL

Unless you increase your pressure, why would you need 2 wire hose? If the pressure is 3000 or less, 1 wire should be fine. (I use 1 wire with 8/3000.) If you like flexible, I would highly recommend a flow-type unloader - it will allow the hose to relax when you're not spraying.

[Ron Musgraves 240]

I always disagree with everyone about this, dont have time right now to reply.

all factors are involved on cleaning units. (heat, pressure and GPM)

the type of job also comes into play. verticle and horizontal work requires different things. heat and pressure have less play on most verticle cleaning, GPM is more important. certain flat jobs more gpm just makes the job more difficult.

I need to answer the in more detail when able.'

Happy New Year to all.

[Ron Musgraves 240]

Buy a six gallon machine if your not certain.

[DAVID V 22]

John, I have that type of unloader.

When I ordered my rig I never that about the hose, I just expected 1 wire.

When he delivered it he said he put the 2 wire on for me.

Single was great on my last rig.

I'm going to replace the 2 wire and keep it for back-up. I'm running 2 5.5/3500 machines/1 hot- 1cold.

[John T 744]

Go with the higher GPMs if you can swing it. They almost always help in speading up the jobs. My Machine below can go from two guys running 5.5 gpms two one operator going full tilt at 11gpm and all of this is at 4500psi. THe Psi I basically have it dialed down to 3500psi because that is all I need most of the time. The higher the GPM the faster the job goes ESPECIALLY if there is alot of rinsing that needs to be done.

My truck below is a propane set-up with a 48 hp Diesel Engine. The combine tanks can hold arprox 900 gallons and there are a few commerical accounts I deal with that have no water hookup(Manhattan) so my water tanks do come in handy.

[MMI Enterprises 289]

Aside from the 2 wire option don't you guys with larger setups in the 8 gpm and up sizes use larger diameter/ heavier hose, boiler coils, etc.?

Please correct me if not so. Would be nice to know what can be used off a 5 on say an 8..

[John Orr 206]

Aside from the 2 wire option don't you guys with larger setups in the 8 gpm and up sizes use larger diameter/ heavier hose, boiler coils, etc.?

Please correct me if not so. Would be nice to know what can be used off a 5 on say an 8..

Same hoses, same guns. Bigger surface cleaners :lgsideway and larger tips on everything.

[Jeff 232]

Thanks for all the great advice everyone. I am going to go with at least 5GPM for now. I did see a machine that pumps 5.2 I think that is the front runner.

Call Bob of Pressure Tek, he sells Pressure pro machines, you can get a 5.5gpm machine or an 8gpm for not much $$$ compared to other machines

One of my trailers has 2 - 5.5gpm machines and one water line intake and it feeds a 250 gallon supply tank and 99.9999% of the time we never run out of water, thats two machines running

My other trailers have a 5.5 & an 8 gpm machine each and we keep two water lines going to it, one isnt enough

[Beth n Rod 1,279]

Ok, I have breezed through this one and feel the only point not covered (unless I missed it) is the consideration of supply flow.

Unless you are tapping a hydrant 100% of the time, you will encounter water supply issues.

Not all commercial hose bibs deliver 4+gpm's which can affect your ability to continually work while on large projects.

Many here have 300 - 500 gallon tanks to help buffer this but eventually the tank can run dry especially if you run low on a previous job before heading to the next as a result of low flow on one or more job sites.

I didn't see a tank size specified in the original question of 4 vs 5 gpm units so I am mentioning this for the basis of consideration of your final decision.

For the benefit from our experience, we have an 8gpm unit (2-gun capable) which helps to get a job done quicker due to the faster rinsing capabilities of a higher flow unit. We have a 180 gallon tank for our unit to draw from. The size is due to constraints of space inside the Sprinter van. If you are intending to mount all of this on a trailer, you may need to consider the load bearing capabilities of it to hold the tank when full (8 lbs/gallon). 300 gallons = 2400 lbs not including the tank weight itself which is about 3/4 lbs/gallon = 225 lbs + 2400lbs = 2625 lbs

The pw'er unit you buy will then determine the overall weight of the load. Then pick your trailer accordingly. Also, can your vehicle haul this load? Need a transmission cooler installed?

For comparison, we are residential service providers for the most part and in using smaller gpm units vs higher ones like a 4.6 gpm unit, we still run into supply problems where we are caught waiting for the tank to fill because of supply water not being sufficient to meet the demand of the unit. Having a large tank does help, but since we can have 2 or more houses in a day lacking in sufficient flow, it slows things down due to waiting for the tank to fill.

Yeah yeah, I hear you guys, get a smaller unit to keep working, but then the pressure to flow ratio drops as well and we cannot wash 3 story houses from the ground as effectively.

Overall, the differences between a 4gpm unit vs a 5gpm unit for commercial service are marginal in my opinion, but considering you are doing commercial primarily, I would recommend the 5gpm unit anyway. The cost is not much more considering in a short time, the higher gpm unit will pay for itself in time saved and more work completed vs a 4gpm unit.

Tank size is a better question for you to consider at this point.

Food for thought.

Rod!~