What is Tru-Gas?
Do you mean this stuff?
TruFuel
Real, pure gasoline (petrol) has an energy density of 34.2 mj/litre
Diesel fuel/residential heating oil, 37.3 mj/L
100LL Avgas, 31.59 mj/L
Gasohol E10 (10% ethanol 90% gasoline by volume), 33.18 mj/L
Jet A aviation fuel/kerosene, 33 mj/L
If you're worried about ethanol, just precipitate it out of solution.
Not hard to do.