[Moriarty]

I was looking at my gas mileage and noticed that the two times I got gas from a 76 station, my mileage was worse (5-6 vs 7-8 normally.. this was before I tuned my carb). This was 92 octane, and I usually fill up with Shell V-Power 92 unless the station only has 91. Two data points isn't much to go on, so I figured I'd ask and see if anyone else has noticed lower gas mileage based on where they fill up?

I also had done some experimenting with the Spirit station nearby which has no-ethanol gasoline but only at 89 octane (both straight and mixed with various octane boosters and leaded race gas). Mostly that all continued in the 7-8 mpg range, which also made the two tanks of 76 stand out to me.

Any ideas why that might be?