I have all flex fuel vehicles now but when I used to run E-85 in non flex fuel vehicles I tried to stay under 50 or 60% E-85 in the winter because I thought it had more trouble starting when it was cold. You are further south so below 0 temps are probable not as big of a problem for you. I never seemed to have any trouble with burning E-85, just some starting issues on the colder days in the winter.