Chuck52
Veteran Member
We drove to Sydney last week , it's a 650 kilometre trip . I filled with straight Unleaded when we left and just made it to Sydney as the low fuel light came on . On our return i filled with 10% Ethanol blend and had no choice but to fill up again 80 kilometers from home . It's a coastal road all the way so it's nearly flat both ways and there was no noticable head/tailwind . Ethanol has a higher octane but it does not get the mileage , i do'nt know how that works . Someone may be able to explain it ?
There is not a direct correlation between octane rating and BTU content of fuels. The octane rating has more to do with the ignition energy, i.e. starting the burn, while the BTU content determines the energy derived from ignition, and the eventual MPG.
Chuck