93 Octane in every tank, in both the Ram (too many performance mods, plus SC on the performance tune) and the '02 Grand Cherokee Overland daily driver (4.7 High Output engine recommends it also). Ouch!!!

 

I use 93 and get 14.0 MPH around town with a MDS Hemi (according to the overhead console)

For those who can find and use E-85, it always lowers mileage about 17% on average.

 

89, cause thats what it recomends.

 

91 octane here, whats 10 cents extra a gallon plus I use the SC perf mode.

 

I use 87. Gives me the best mileage and performance. Thats even after I tried a 3815 with the performance tune. Go figure.

 

At least 89, either by mixing 87 and 93 to get ~89-91, or just getting straight 89. I accidentally put a tank of 87 in my 300C once. She was NOT a happy girl. The truck doesn't seem to like it, either. It had 87 in it when I bought it. Ran pretty poorly 'til it had a tank or two of 89 run through it. I know the book says 87 is acceptable, but he's not happy with it.

 

89 octane 'cause of my mods.

Speed Safely,
AL