I know the owners manual for my 2013 Challenger R/T Classic 5.7 Hemi recommends usage of 91 Octane fuel. Has anyone ran 87 in theirs? If so what have been the issues if any? Just curious. In my 2007 5.7 Hemi truck I purchased new, I have used 87 octane in it most often without any problems thus far. It has a little over 35,000 miles on it.