Not knowing about E-85, I stopped for gas one night in N. Dakota. Got half a tank of E-85. With in 10 minutes of leaving the station my car started coughing and missing bad. The check engine light came on, and I got concerned. Here I am out in the middle of no where in N. Dakota in the Middle of the night. Car acting up and I don't have a clue as to the problem. Crusing speed dropped from 80 to 65, caar would not go over 65 period. I kept going till I reached 1/2 tank, pulled off the road intending to get fresh fuel. If I let the RPMs drop below 4,000 the engine would stop. I pulled in filled up with High Test. Had a hard time restarting the engine, but once I got it going again not letting it drop below 4K I pulled back out on the high way. Five miles down the highway the check engine light went out. Another five miles and the engine smoothed out and once again had pep. I punched it and was at 100mph real quick like normal. Reset cruise at 80 and went on south.