"Are you sure about that? Lets construct a similar situation, but w/ the same fuel to simplify energy content issues. Lets say my car gets 25mpg. I get a gallon of fuel from Shell, Arco, Exxon, and Ned's family gas station. Then I drive 100 miles. Technically, since I used a little bit of each station's gas, I went 100 miles on Shell, 100 on Arco, etc... And since, like ya mentioned, I was using equal parts, I got 100mpg on Arco, and on Shell, etc..."
Your math is off here.....If you have equal parts of each then they are all weighted the same when getting an average. 100 miles driven on 4 gallons is 25mpg any way you slice it. Each gallon is weighted the same at 1/4 the total or 25%. Do not know where you got 100mpg. That would be weighting each gallon at 100%. Maybe you were
on how I came up with my figures.
We're using diesel at 60mpg, and a gallon of propane, be it a GGE or GDE of propane, or a gallon in terms of volume, at 20mpg. To go 20 miles, we used 1/3rd of a gallon of diesel, and one gallon of propane. If it's a gallon of gasoline or diesel equivalent propane, then we used ~37-42kWh of propane, plus another 14kWh of diesel, to go 20 miles, which works out to ~51-56kWh for 20 miles that is the equivalent of ~1.21-1.33 gallons of diesel, so over 20 miles we're looking at ~15.1-16.5mpg. If it's a straight up gallon of LPG, then it's ~28kWh of propane, plus 14kWh of diesel, for ~42kWh/1 gallon of diesel, and that's ~20mpg. Either way, it ain't 40mpg or 30mpg. ~15-20mpg is the norm for a conservatively driven pickup. Not to say that diesel pilot ignition of propane or natural gas isn't more efficient, just that it's not 30-40mpg more efficient.
I think I may be a little
here. Could you explain this more?