Switching from 87 to 93 octane made a difference!

[asgadf/lkjnadsfg]

Gas mileage seemed to average around 10.5-11mpg coming back. Obviously many variables can affect mpg, but I concluded that it was worth using higher octane and or ethanol free when towing my TT.

There's also over 7,000 feet of elevation drop between Yellowstone and Chicago. I did a similar trip last year, but I ended in Memphis, which is 400 feet above sea level. It was much easier on the fuel coming back than it was going out.

Good mileage or bad, just talking about it makes me want to go back.