I was talking to a buddy about this and it wasnt that clear what we figured out. This is more fun than anything. If i have to buy a permit $240.00 to burn propane in a truck that gets 10 mpg and propane is 00.70 a gallon cheaper than gas how many miles will i have to drive to pay for the permit? I know it will burn more propane per mile than it would gas but agin its just for fun and dosent really matter .
I have used propane, and it gets really low MPG. I'd need to know the actual prices Doug. Carbon atoms are carbon atoms. Folks make all sorts of claims, but the BTU output of a fuel tracks with the weight, not the volume. gasoline is ~125,000 BTU per gallon and ~6 pounds propane is ~91,500 BTU per gallon and ~4.24 pounds. Propane gets about 75% of the fuel economy of gas.
Propane would get you 7.5 mpg rather than 10, 100 miles uses 10 gal of gas at $3.70/gal is $37 100 miles uses 13.3 gal of propane at $3/gal is $40