jlsoaz
Well-known member
wwhitney said:Your comment got me curious so I decided to check wikipedia. The fuels commonly called gasoline produce between 111,000 and 115,000 BTUs/gallon, so the range is much tighter. But diesel produces 130,000 BTUs/gallon, while E85 produces only 82,000 BTU/gallon.jlsoaz said:My understanding (and going from memory) is that a gallon of gasoline when combusted will release anything from (very roughly) under 100,000 btu to more than 130,000 btu.
Cheers, Wayne
Hello Wayne,
if we go by the link you provided, then I guess, but it is just one link. I suppose it is possibly correct that that the range in reality is tighter than the range of numbers I ran into when researching this years ago, but I think part of the problem is if I checked different sources I ran into different numbers and sometimes differing more widely than you have mentioned. If we take a quick check now we see also this:
https://en.wikipedia.org/wiki/Gasoline#Energy_content
Gasoline contains about 42.4 MJ/kg (120 MJ/US gal, 33.3 kWh/US gal, 120,000 BTU/US gal) quoting the lower heating value. [6] Gasoline blends differ, and therefore actual energy content varies according to the season and producer by up to 4% more or less than the average, according to the US EPA.
In my own calculations I eventually ended using something in the 33.x-34.x kWh per gallon range.
It has been too many years since my last chemistry class for me to have a handle on incorporating LHV and HHV understanding into the conversation, but the point was and is basically that when I went to look into these things, I found a range, and this brought home that the energy released when combusting a US gallon (or for that matter, a kilogram) of the fuel is not consistently the same across all gallons and this is logical I think because it is not just one set molecule but
"It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives."
This is not to treat wikipedia as that reliable, but for purposes of a quick look at something.