There is a good and long thread about this on the 5.0 page but it seems more than a few of the comments pertain to the Ecoboosts (both 2.7 and 3.5). Seemed to make sense there is a thread for the two Ecoboost engines as they are obviously very different than the 5.0.
I've only run 87 octane in my 3.5, or 88 octane e15. 88 e15 should perform like 89 octane for the simple reason, you need a higher quantity of fuel with e15 and that fuel has a cooling effect in the cylinders.
With 88 e15 I...
87 octane vs 93 octane - ECOBOOST
I've only run 87 octane in my 3.5, or 88 octane e15. 88 e15 should perform like 89 octane for the simple reason, you need a higher quantity of fuel with e15 and that fuel has a cooling effect in the cylinders.
With 88 e15 I...
87 octane vs 93 octane - ECOBOOST