I have been hearing about SC cars running hot because of ethanol use.
My question is scientifically speaking, why does this happen? Also, if this can happen on the track, can this happen to a flex-fuel street vehicle that runs E85 when it is 100 degrees outside (like today) and you are sitting in traffic? Does a flex-fuel street vehicle come with a bigger or different cooling system to fix this?

This is not meant to be another ethanol/USAC bash fest. I would really like to know what causes this issue.

Thanks.