Originally Posted by Ziggyrama
That is possible. The stickers in the gas station say "up to 10%" ethanol. We could be getting 10% or 5% or 1%. Perhaps we get more ethanol in the mix in winter months and the content drops in summer. I tried to look for this info but it's not easily found. No one at the station can even point me in the direction of where to go to find out. I think the best way to know is to take a sample and test it and do it on periodic basis to find out what's really in it. Another thing to think about, as corn prices rise and ethanol becomes more expensive to produce, I imagine gas producers may cut the blend down to keep the prices from rising too much. I am sure they're under pressure to keep it as low as possible. May have an effect on how much is added to the mix.
That's because most gas stations are privately owned and only carry the fuel of the big company. Then there's the fuel distributors that move the fuel. Then there's the parent fuel company. Twice removed from the actual data and the actual parent company doesn't care to share their formula with you. Then there's the fact that there are variances regardless. Fuel in the tanks is never empty, rain water dilutes it sometimes, testing done on site also gets put back in the tanks. There IS no exact number. There is not a single person who can tell you the correct answer except somebody that will test on site.
There's your precise answer.