Street car engine....

[69 GTX]

I know here in Iowa even though it's called 15% it can be higher in winter as opposed to summer.

 

[fbs63]

E85 is 15% 87 octane and 85% ethanol. Winter blend is E70. Its needs STRONG spark. The lower the A/F ratio the stronger the spark is needed. Add boost and a Msd 8 is needed.