I have always wondered how much more effort/work is put into the higher grades of fuel:
87 vs 89 vs 91 vs 93....
I find it strange that no matter how high gas in general gets, the different grades are only seperated by about 10 cents. Which at this point is why I dont mind the extra 2.50 a tank to fill with the better grade. Just wondering.

 

Not much, the higher octane is a result of the additives. Most gas now gets it’s octane from ethanol. Refineries used to add MTBE, Methyl Tertiary Butyl Ether. They used this in the past, but is being phased out where it is still used. The 10 cent different between the grades is a mid US thing. Down in Florida, the higher grades are much more expensive. I have seen some stations in the Midwest with the same price for regular as they sell premium, so it makes you wonder.

My sister-in-law works for a trucking company that delivers gas for a large chain that claims to use special guaranteed gasoline. They buy their gas from one of three terminals in the area, and that is the terminal which is selling the gasoline the cheapest. The trucking company buys the gas priced in the 1000th of a cent, so she gets price quotes on the hour from these terminals. The one with the lowest gets the business, even if it is $0.001 cheaper.

 

I live in Florida and thats the price diff. I see, it's only 8-10 cents between, but thank you for the explanation.