Perty inneresting.
Apropos of some recent diesel discussions, diesel fuel all by itself should give 13% more mpgs, just from the higher btu's per gallon alone. And, funnily enough, diesel appears to be about 13% more expensive at the pump!!?? Conspiratorial coincidence?? lol
It also becomes clear how gasahol shoves it in the motorist a little deeper, as well -- radically lower btu's per gallon.
Unbeknownst to most people, regular gas has more btu's/gal than high test -- by dint of the higher stability of the tertiary carbocation intermediate, in the combustion process.... no foolin. Texaco was successfully sued over this li'l factoid, in their false advertising of their premium fuels. Someone at Texaco didn't pay attention in Organic Chem I.
#6 fuel oil has markedly higher energy per gal:
The thing about #6 fuel oil is that it may need little to no fractionating at all, radically lowering its delivered cost. Yeah, the sulfur.... But mebbe by adding another mere 500 lbs to each vehicle, they could f*ck us for a de-sulfuization unit in each car.....
Some other useful charts:
Fwiw.