Reader wonders if price variance in octane levels greed in petroleum industry

I have been asking a question since last fall and no one seems to answer it.

Ever since I’ve been driving, there has been a 10-cent variance in the price per gallon of gas among the various octane levels.

For example, a gallon of 87-octane gas would be $3.50 a gallon while 89-octane gas would be $3.60.

In fact, I just recently made a trip from St. Louis to mid-Indiana and found the 10-cent variable in Illinois and Indiana. But for some unknown reason at the end of summer last year, the gas stations on Telegraph Road changed the price from 15 to 17 cents a gallon.

My question is: Have there been some advancements made in the various octane levels to improve mileage or is this just another example of greed in the petroleum industry?

John Kienzle