# Generator Fuels - Gasoline vs Propane



## Predator (Sep 19, 2017)

I have 3 generators. One Coleman Powermate 6520, one Honda EU2000i and one Predator 3500 Inverter. All currently run on gasoline.
Starting to explore the use of propane. I keep 60lbs of propane on hand at all times for cooking in case of power failure.

Here's what I've found so far......

PROS
1). Runs cleaner....no carbon buildup
2). Propane can sit in tanks for a VERY long time vs the relatively short "shelf life" of gasoline.
3). Propane is safer to store than Gasoline

CONS
1). Propane is more expensive (the basic rule of thumb is 5 gallons of gasoline is ~= to a 20lb tank of propane (~$19.00 vs ~$14.00) (shop around)
2). You need a regulator and special equipment that can cost up to $350 to convert your generator to propane
3). Many propane filling stations will charge you the full price whether your tank is empty or not...possibly further raising the cost for propane

By far, the biggest advantage to propane seems to be shelf life. If you happen to have a 100 gallon propane tank, the cost per gallon can become competitive with gasoline.

As far as the carbon buildup....you can minimize this in gasoline engines by using SeaFoam.

Gasoline can be stored in airtight containers with fuel stabilizer for up to 2 years, but after about 6 months, the fuel chemistry begins to breakdown and will not run as clean as when fresh. Time is not a friend to gasoline storage.

I think the ideal situation might be propane, stored in 100 gallon tanks outdoors. You could run high efficiency generators for a good while off of 100 gallons of propane. Imagine an inverter generator that could run 8 hours on one gallon (my EU2000i can) . That would give me 800 hours of run time.
Or, approximately 33 continuous days....or more realistically...100 days of running it 8 hours per day. Bada BING !!

And the beauty of it would be that it could sit for a very long time until I needed it. Even decades.

Yep....gonna start looking into propane conversion kits.


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## thehandyman1957 (Feb 11, 2017)

I'm a big fan of Propane gen sets. Just remember, you don't get the same btu's from Propane as Gas. I think it's about 12-15% less.
But the trade off is that it lasts for a very long time and there is no carb gumming issues and the engine runs clean. 

Keep this in mind though, Gas acts as a cooling agent for generators and for the valves. If you convert a gas gen set 
to a propane system that was never built or intended for propane you could burn valves very quickly.

Instead, I would look for a generator that was designed for propane so you know the valves were built to handle the extra heat.


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## Predator (Sep 19, 2017)

Excellent information!

You know, I run into this with my Flex fuel vehicle. It feels sluggish and the mileage drops a good bit when I use E85 vs regular fuels.

I would imagine the genset might have to work harder to produce the same power utilizing propane?

I work on a LOT of engines ranging from car engines to motorcycle engines to scooter engines so I've practically seem it all. What I have NOT dealt with it propane powered vehicles. I do know the incoming gasoline charge cools the engine. 

Very good point about the btu's.

Is it possible to adjust the mixture, so to speak, with propane as you can with gasoline engines? Does metering more propane per cycle have the same effect as enriching the mixture on gasoline engines?


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## aandpdan (Oct 8, 2012)

I have two generators, a 10hp Tecumseh 5kw and a 7 hp Briggs 3kw. Both are converted to run only on gaseous fuels.

Yes. You can adjust the mixture just as you would with gasoline.

As to power loss, I've not noticed any. For one thing, both engines run MUCH smoother than they ever did on gasoline. Secondly, the limiting factor is the load on the generator head not the load on the engine.

Another bonus, the oil stays cleaner. No fuel dilution.

Dual fuel is an option too.


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## Predator (Sep 19, 2017)

aandpdan said:


> I have two generators, a 10hp Tecumseh 5kw and a 7 hp Briggs 3kw. Both are converted to run only on gaseous fuels.
> 
> Yes. You can adjust the mixture just as you would with gasoline.
> 
> ...


What about costs?
Do you buy it by the 20lb tank or in larger quantities?


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## RonJ (Aug 5, 2015)

Is availability even or close to if you need propane I say this thinking if you have a LP Distributor within driving distance, that would be good. Like others I have 3, a Honda 2000i, B&S 6250, and a 7K; I live rural, but have places to get LP about 30 miles away, but still feel better with the gas. I really like the idea how much longer it will last etc....i guess I am too old to change now. Ron


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## aandpdan (Oct 8, 2012)

I can refill a 20lb (or bigger) tank at most any hardware store or exchange it - worst case.

Yes, I've run it off a 20lb but I have propane for the house and run it off those 250 gallon tanks.


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## Predator (Sep 19, 2017)

aandpdan said:


> I can refill a 20lb (or bigger) tank at most any hardware store or exchange it - worst case.
> 
> Yes, I've run it off a 20lb but I have propane for the house and run it off those 250 gallon tanks.


Ok, because I know that at least with Amerigas, if you buy it out of season (during the hot months) in quantities of 100 gallons or more, you can get a substantially better price than if you go get a 20lb tank filled impromptu.

IIRC, it's over $1.00 per pound difference.

That makes all the difference in the world when it comes to the cost of running it on Propane vs Gasoline. YUGE difference.


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## exmar (Jun 29, 2015)

I live in the country and have a 375 lb. propane tank for heat and cooking. We don't have enough outages for me to think about converting or buying a dedicated propane gneset. I've had no problems with leaving the gensets full with Stabil added, then, once a year drain and put into one of the vehicles and refill with fresh gas, stabil and a shot of sea foam. 


Last time I looked, it's difficult to buy a "propane" genset in the smaller sizes, a.k.a. "portable" generators. Generac had one for a while, weird looking thing, had a bracket on the back for a 20lb. cylinder. I was mildly interested and called Generac and asked them about providing a quick disconnect to piping from a large propane tank. "Absoloutely NOT! That would void the warranty and is illegal.  It seems that "propane gensets" tend to be in the whole house range, 10KW+ However, it's been a while since I looked. Obviously any gas engine can be converted to propane, the only question would be how much do you value the warranty, if any, etc.


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## exmar (Jun 29, 2015)

exmar said:


> I live in the country and have a 375 lb. propane tank for heat and cooking. We don't have enough outages for me to think about converting or buying a dedicated propane gneset. I've had no problems with leaving the gensets full with Stabil added, then, once a year drain and put into one of the vehicles and refill with fresh gas, stabil and a shot of sea foam.
> 
> 
> Last time I looked, it's difficult to buy a "propane" genset in the smaller sizes, a.k.a. "portable" generators. Generac had one for a while, weird looking thing, had a bracket on the back for a 20lb. cylinder. I was mildly interested and called Generac and asked them about providing a quick disconnect to piping from a large propane tank. "Absoloutely NOT! That would void the warranty and is illegal.  It seems that "propane gensets" tend to be in the whole house range, 10KW+ However, it's been a while since I looked. Obviously any gas engine can be converted to propane, the only question would be how much do you value the warranty, if any, etc.


 
To clarify, there are dual and tri fuel portable gensets out there, but one dedicated to propane doesn't seem available. Just checked the Generac site and they've removed the one they had. It seems to me that they're missing a market. Lots of folks in the country have large propane tanks available. Add to that, in rural areas, outages tend to be more common and we all have gensets in the barn or wherever that we pull out when needed. All the advantages of propane over regular gas in an engine that doesn't get a lot of run time. If someone offered a propane genset with a quick disconnect (think of a gas grill with a connector to natural or propane gas on the patio, etc.) That would be great. The dual and tri fuel units seem to be set up for 20 or 30 lb. tanks, so a slight plumbing modification would be required, perhaps voiding warranties? Just musing, would be neat to drag out a genset, connect propane, start, connect your house and that's it. Shut down periodically to check, oil, etc. Perhaps offering a "propane" engine on a smaller, (5KW?) genset would put it beyond the acceptable price point.


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## Predator (Sep 19, 2017)

exmar said:


> Perhaps offering a "propane" engine on a smaller, (5KW?) genset would put it beyond the acceptable price point.


I think this. Remember, they can't do things the "cheap" way due to liability. So that could add $300-$400 to the cost of a $700 gasoline generator.

DIY is probably the way to go with Sub $2000 generators for propane.


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## ngyuen (Feb 13, 2019)

Predator said:


> I have 3 generators. One Coleman Powermate 6520, one Honda EU2000i and one Predator 3500 Inverter. All currently run on gasoline.
> Starting to explore the use of propane. I keep 60lbs of propane on hand at all times for cooking in case of power failure.
> 
> Here's what I've found so far......
> ...


We bought a gas Gen and converted to propane for all the reasons listed above. It works great! No fuss no muss.

We have a few smaller tanks but will get a 250gal tank put in this summer. We will have it set up so we can fill our smaller tanks with it. Also by hooking up the Gen to the big tank then you don't have such a problem with it in the cold like you do with smaller tanks. Prevents having to go out and rotate the tanks repeatedly. 

Being able to fill smaller tanks at home gives us versatility. It's the easiest cheapest safest (no way will I store gas in the barn) way to get heat/light to the barn green house camping equipment and such. If we had to bug out we could have a full tank to take with us.

Propane prices will rise with gas prices but not as high / fast. I hope. But at least you can use today on yesterdays prices (until you run out) Also the guy that helped us with the Gen conversion has a tank in the bed of his truck he just flips his truck to run on propane.

We are many years out before we can say we make our own fuel. So I figured this is the next best thing. At least this is what works for us.


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## KRE (Nov 29, 2011)

ngyuen said:


> We are many years out before we can say we make our own fuel. So I figured this is the next best thing. At least this is what works for us.


If you research Wood Gas, you can be making your own as soon as you build or buy a Gasifier. Lots of videos of wood Gasifiers on You Tube. If you build or buy make sure it's sized to your needs/wants. https://www.build-a-gasifier.com/Gasifier-Kits/


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## RandallBone (Sep 30, 2020)

Your post greatly inspires me to purchase a propane generator at my house. In the last couple of months, I am searching for an energy-efficient propane generator. I found two models on the Internet- DuroStar DS10000E and Sportsman GEN4000LP. Between these two models, which generator you think is better?


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## RandallBone (Sep 30, 2020)

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## jkingrph (Sep 18, 2017)

exmar said:


> I live in the country and have a 375 lb. propane tank for heat and cooking. We don't have enough outages for me to think about converting or buying a dedicated propane gneset. I've had no problems with leaving the gensets full with Stabil added, then, once a year drain and put into one of the vehicles and refill with fresh gas, stabil and a shot of sea foam.


A couple of years ago I added a couple of the little Honda 2000eu gensets and converted to be able to use propane, and find they work quite well. It's nice to have the dual fuel capability. At least this way I can keep the carburator dry and not worry about it gumming up, or when using gas having to turn the generator over to drain the tank. I only used them once during a short outage, and that was just to have some lighting so had it outside on the patio, with an extension cord running in to a lamp. My big 11000 watt generator is gasoline only, with a steel tank. I always add as recommended a double dose of a stabilizer and then a shot of two cycle(outboard motor) oil to help prevent any tank corrosion and to lubricate seals and lightly coat inside of those carburetor parts that might be subject to oxidation. I really never measure it but estimate my final oil concentration at about 1:500, low enough I never notice any smoking. I aways turn the valve off and run the carburetor dry after using, and I did install a "T" fitting and drain valve so I can do as you , drain the tank and run that gas in my lawn mower, don't want to put that mix in my car with a catalytic converter. Been doing that for about 18 years now with no problems.


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## olivia (Jan 22, 2021)

Propane is more expensive however it is more reliable and need less Maintainance to I like propane. But both are of same types I have researched a lot about it on the internet but got only one article which was in detail and came up with some solution.


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## billt (Dec 11, 2020)

I purchased 2 Westinghouse 9500 Watt Dual Fuel Generators. Both run very well on both gasoline and propane, and produce excellent power on both. The only downside with propane, is it doesn't produce as much power as gasoline. Because there are fewer BTU's in a gallon of propane, then in a gallon of gas. But it really isn't enough to worry about.

The benefits far outweigh the negatives with propane. I have a 40 pound tank on wheels, that can be used either vertically, or horizontally. A 30 pound, and 2, 20 pound bottles, for a total of 110 pounds. I can buy propane here for as low as $2.49 @ gallon. I can also get 93 octane unleaded, non ethanol marine fuel for $3.99 @ gallon. Treated with a healthy dose of PRI-G, it will last a long time. So with 110 pounds of propane on hand, along with 3 vehicles with full tanks, for a total of 78 gallons of gasoline, I can make power for a good long time. Both of my units start up and run well on either gas or propane. And you can switch fuels on the fly, which is also nice.


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## Robh (Aug 19, 2019)

Well this thread didn't age well. There are tons of propane and NG conversion kits available for any gas generator of any size these days. My Honda EU2200i has the Hutch Mountain one.

But to the original thread, I think the best answer to whether you should convert to propane over gas might be how much you use it? I hardly need my generator, so it's nice not having to worry about gas. To me that's worth the extra conversion cost. Plus, I can still use gas if I want. Having options during an outage is good.

It is a similar thought process with my 2-cycle leaf blower. It's the only 2-cycle engine I have left, so I buy TruFuel for it. Sure it's more expensive than mixing your own gas & oil, but I use it so infrequently that the cost really isn't a factor over the convenience.


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## iowagold (Jan 22, 2020)

these days fuel choices is an excellent way to go!

for me here natural gas is my primary fuel choice.
then gasoline
then lp as the last choice.

but i am in town, 20 miles from the main central usa natural gas pipe line with a BIG pumping station at that location.

one of the BIG down falls for natural gas is plastic lines are drilled through tree roots..
so if you get severe winds like in the dechero or a f4 or f5 tornado then you are talking about trees up rooted and breaking of the natural gas main.

and both natural gas and lp motors need warmer intake air when below 10 deg f..
that is where a gen shed works out great!
50 deg f to 70 deg f is a good working temp for gen sets.
make sure to have the crankcase vent heater option for cold weather!

99% of the time for me I can run on natural gas!
way cheaper per hour to run.
and a lot less trash in the oil!


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## speedy2019 (Jan 29, 2019)

Propane doesn't like the cold


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## iowagold (Jan 22, 2020)

kinda like diesel in the cold...
if it is warmer temps above 20 deg f it works better...

and at those cooler temps intake air pre heat is nice to hold down the icing.
that is where a gen shack helps on that...

and an lp tank blanket helps with tank pressure.


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