I was at a gas station that I am not familiar with and put Unleaded 88 in my car thinking it was normal gas. Later found out it is really gas with 15% ethanol. I am worried that this could cause damage to the engine or other components. It’s been running fine so far. Should I be concerned about running this tank of E15 gas?

 

I think you will be ok. Run 1/4 to 1/2 tank out and top it off with 91 or better pure gasoline if you can get it in your area. I run 89 10% all the time and get over 17mpg on my 100 mile run everyday.