[PaleMelanesian]

Originally Posted by gasman

Just buy ethanol-free gas. That's an immediate fuel-saving blend of 3.3%.

math...

ethanol contains 2/3 the energy of gasoline. Ethanol blends are generally about 10%. 2/3 * 10 = 6.66. Add back in the other 90% at 100% of gasoline's energy (which is exactly 100% because it is gasoline), and you get ~96.7... 100% - 96.7= 3.3333% That is your fuel efficiency loss per volume of pump fuel (no matter how much or little). So, just go back to 100% gasoline, and you get that back. That's what I do. It costs the same, too.

If you read carefully, that is theoretical based on energy in fuel, which is not the same as how much power you can get from the fuels in a gasoline engine. It just so happens, though, that tests have been done (extensively) and, in motorvehicle gasoline engines, those theoretical numbers match up to the tests very closely. And if you don't believe that after researching to find the test numbers, then just go try it yourself.

I highly doubt a 1% fuel efficiency boost is outside the margin of error. It says "up to" a number. That's statistics talk for "BS number." Up to means nothing. A statistically significant average different than original (when done properly) might have meaning. But I doubt those tests were ever done. Anyone want to take bets on whether it was a true double-blind study? lol

It's all BS.

Looking at the EPA ratings for flex-fuel vehicles bears this out. Their E85 mileage is on average 71% of the gas mileage. The energy content of E85 is about... 71% of gas alone.