A random thought

A couple of years ago, while driving across country from East to West, I noticed that the octane ratings for "regular" gas at the pumps were lower west of the Mississippi than in the East. Throughout much, if not all, of the East, regular gas has an octane rating of 87. Once we were west of the Mississippi, the ratings for normal gas were 85. I don't know whether this is a state by state thing or a more general East v. West thing, but regular gas seemed to be 85 octane pretty consistently in the Western states we drove through.

I don't have a clue why there should be a consistent difference. If anything, you would think that the more mountainous West would call for higher grade gasoline than the rolling hills of the East.

But, one thing it does suggest to me is that gasonline pricing comparisons between eastern and western states may be tainted, for whatever that's worth.