Original sale thread over on that other site:
https://www.ar15.com/archive/topic.h...&f=17&t=680532

Rep says runtime is similar for a 5gal gas can to 20lb propane tank

Some other stuff from that post, not sure the math is 100% solid. There are some other sites and info I have stashed on a laptop somewhere - will dig it up later if I get a minute.


Originally Posted By EXPY37:
Originally Posted By MAGICmaker:
Check the U.S. CARB website. Look for the section labeled "CONSUMPTION ". Rule of thumb
Is 1000 BTU X HORSEPOWER per hour at WOT. NATGAS is billed in THERMS, one therm
Being 100,000 BTU. After you wade thru the math you'll find the cost of operating on
gasoline to be 4X the price of NATGAS, and propane being 2.5X the price of NATGAS.
Of course this will be dependent on your local prices. As long as you've tuned the
Regulator per the included instructions, with a Tachometer, your numbers should be in
line with your generators output in horsepower.

ETA: My local numbers, non-ethanol gasoline $3.00 gal, propane $2.19 gal, NATGAS $.79 THERM.
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Since gasoline has about 115,000 BTU's per gallon... [unleaded]
And propane has about 90,000 BTU's per gallon...
Per hour...
Propane has about 3/4 BTU's of gasoline...
IIRC.
And since propane is about 75% the cost of gasoline at your location...
Doesn't that make them closer to equal in cost per HP developed?
BTW, according to the first link I pulled up, they are saying one HP is ~= 2540 BTU's per hour...
Link