Didn't know ethanol is supposed to be bad for your vehicle. Living in the Midwest, we promote this fuel! I recently have been consciously using more ethanol gas and find it has significantly increased mileage reported by my vehicle. Too, I'm going to suggest you try a different gas station. With my previous vehicle that service engine light came on when I gassed up at a certain station. I found I needed to nix purchasing there and stick with one "brand" gas.