LP Consumption for a 5500-Watt RV Generator

[Dan_Frisbie]

I have a 2026 Brinkley G3520 with the flex-fuel generator. We never boondock and I do not plan to put gasoline in the generator tank unless I have to.
Since we live in Florida, the generator will likely only see use in case of power failure after a big storm.
What is the average LP consumption rate when used as generator fuel?
With a power outage, we’ll likely be staying in the camper, running two A/C units, fridge, TV, etc..

 

[whiteva]

What make and size generator?

 

[Dan_Frisbie]

What make and size generator?

5500 watts. Uses about .5 to .75 gallon of gasoline per hour.

 

[Primerump]

propane has approx. 82% of the btu's so you will use approx. 1.2 times the fuel vs gas.
therefore 0.75*1.2 = 0.9 gal.

 

[Dan_Frisbie]

Anyone that has used their propane generator care to chime in?

 

[RayIN]

I have a 4,000w portable genset. It will consume a 20# cylinder in 20- 24 hrs. depending on load.
Like you, I never plan to add gasoline to the tank, but will if required.

 

[Gary RV_Wizard]

I have a 2026 Brinkley G3520 with the flex-fuel generator. We never boondock and I do not plan to put gasoline in the generator tank unless I have to.
Since we live in Florida, the generator will likely only see use in case of power failure after a big storm.
What is the average LP consumption rate when used as generator fuel?
With a power outage, we’ll likely be staying in the camper, running two A/C units, fridge, TV, etc..

What make & model of generator is it? The manufacturer often provides fuel consumption data at different wattage loads, e.g. 100% of max, 50%, of max load, etc. For dual fuel models, both gas and propane estimates are given. It may be in your owner manual or a brochure.

As primerump explained, propane has a lower energy content than gasoline. The US Dept of Energy says that 1 gallon of propane is the energy equivalent of 0.74 gallons of gasoline. That means it takes 1.35 gallons of propane to do what 1 gallon of gasoline does. For ease of comparison, a common "rule of thumb" states that LPG (propane) consumption will be about 25% higher than gasoline consumption, even though the lab measurement says it's a bit higher than that.

My Firman WHO3242 (3200 watts, dual fuel) uses 1.25 gallons of propane to do what 0.9 gallons of gas will do.

As a practical matter, it is very difficult to project how much fuel will be consumed when the watt load varies, as it does with cycling loads like refrigerators, water heaters, air conditioners, & battery chargers.

 

[DutchmenSport]

The only way you will know how efficient, or how inefficient the generator is, is to try it. Make sure your your propane tanks are full, unplug from shore power and try it out. See how long the generator runs until you are out of propane. Then you will know for sure what to expect.

Yes, you will burn through a tank of propane, but then you'll know for sure how long you can expect on YOUR tank with YOUR equipment. The minimal cost to refill the tank will help you more than you realize in planning for events when no electricity is available.

This is the only sure-fire way you will know what to expect in the future.

 

[Dan_Frisbie]

I have a 4,000w portable genset. It will consume a 20# cylinder in 20- 24 hrs. depending on load.
Like you, I never plan to add gasoline to the tank, but will if required.

THIS is exactly and all I needed.
Thanks, Ray.

 

[Kirk]

propane has approx. 82% of the btu's so you will use approx. 1.2 times the fuel vs gas.

Or at .75 gallons per hour of gasoline, propane it will use .9 gallons of propane per hour. A 30# propane bottle holds 7.1 gallons of propane so you would use a bottle in roughly 8 hours, assuming that it is the only thing using propane. If you use the 1.35% then only 7 hours.

 

[OldWEB]

It was soooo hard to give us the make...

From the manual:

 

[rpnelson]

I have a 2026 Brinkley G3520 with the flex-fuel generator. We never boondock and I do not plan to put gasoline in the generator tank unless I have to.
Since we live in Florida, the generator will likely only see use in case of power failure after a big storm.
What is the average LP consumption rate when used as generator fuel?
With a power outage, we’ll likely be staying in the camper, running two A/C units, fridge, TV, etc..

I haven't used a propane generator myself but a friend of mine has a 5500 watt generator on his Hitchiker fifth wheel with two air conditioners and he says it uses a 30 lb. cylinder every day in warm weather.

 

[Gary RV_Wizard]

two air conditioners and he says it uses a 30 lb. cylinder every day in warm weather.

What does he consider warm? A 30 lb cylinder is 7.5 gallons and that's actually not a lot if the a/c's are running non-stop for many hours.

 

[rpnelson]

Don't know what the conditions were or how warm or how many air conditioners he ran. Just said he had to fill a 30 lb. cylinder every day. I am not familiar with propane generators myself but I think they use more fuel than a lot of us believe. I have used a 4000 watt gasoline generator in low to mid 90s running a 13,500 BTU air conditioner most of the day and about half of the night and it would use around 10 gallons of gas in 24 hrs.

 

[Lou Schneider]

I am not familiar with propane generators myself but I think they use more fuel than a lot of us believe.

Propane contains about 25% less energy per gallon than gasoline, which means an engine operating on propane needs about 25% fuel than the gas version.

The gasoline Onan 5500 is rated at 0.3 GPH (gallons per hour) at no load, 0.6 GPH at half load and 0.9 GPH full load. The propane version is rated at 0.4, 0.8 and 1.1 GPH respectively.

 

[rpnelson]

Those numbers in gallons per hour would be helpful to make a comparison. Old Web posted a helpful chart too from the Onan manual but the gasoline numbers were in gallons and propane numbers in pounds. It looks like you might use most of 2 30 lb. cylinders a day if you had to run 2 air conditioners during much of the day. Dollar wise, the cost of running generators could be $40 a day or more in hot weather. Guess I can't complain much about my electric bill.

 

[Kirk]

. Dollar wise, the cost of running generators could be $40 a day or more in hot weather.

We found that in really hot weather with the a/c compressor running most of the time it cost nearly as much in gasoline as the cost of most RV parks. In recent years the price of gasoline is much higher and so too are campgrounds, so I suspect that the comparison is still pretty similar.