scrappy isb67
Gold Member
That's probably not true, as octane is separate and independent of the fuel, whether it's gas or ethanol. The gas or ethanol doesn't naturally have octane in it.
What is true is that ethanol contains about 15% less energy per volume than gas. So you really start to lose out when mixing ethanol into gas. It's actually noticeable if you can carefully measure and track MPG on a vehicle.
octane is a measurement of the flammability of a fuel, as in how fast and smoothly it burns. a low octane fuel burns quick and roughly whereas a higher octane fuel burns slower and smoother. the only difference between the different grades of fuels is an additive that alters the base octane rating of the gas to achieve the desired octane rating. and the octane rating of ethanol is higher than regular gas.
the BTU content has NOTHING to do with the octane rating.