RichSNJ
Well-known member
So I have a V8 GCL on the way and I've read that while Jeep "recommends" 89 octane, 87 is "perfectly acceptable". Since it's 40 cents more a gallon, or about 9 bucks a tank, I don't plan on using 89 unless there is a significant reason to. Anybody out there use 87 or 89 in their 5.7 Hemi and have experiences either way? What about octane booster products? I have a v8 Mustang that I've never put anything other than 87 in and have never had an issue.