Fillup prior to leaving Wisconsin for Pennsylvania

I just added 2.5 gallons of E85 to 5.85 gallons of E10 to my tank. My Ford Dash readout reported 28.4mpg while the scanguage reported 29.7 mpg for the last tank. This was in 11-22 degree weather and about 90% of it on two lane state highways (traveling to nordic ski areas) with a 55 mph speed limit. The local E85 pump carried a price of $2.39 while E10 was $2.79. I leaving on Monday for Pa with a likely stop in Michigan.