As stated before I have tried both grades and did not see any difference in performance or better gas mallage. I have actually got the best millage on 87. As far as some people making statements about driving like old people by some, I am 63 and I like to use the power my 300C has. It will smoke the tires when I want it to. I love to wind it out when I am where I can and on the highway when it is clear I like to run it up to the 100 to 110 MPH, and it will do it very quickly with out any hesitation. Other Mopars in my family will run the quarter mile in 13,12 and 10 seconds and my son is very high up in one of our country's largest manufacuring company's of high performance parts/eqpt. and I have been a Drag Racer all of my adult life. The other cars we have require highter octane rating, but with the technology used in the 300C and what it says in my owners manual I fine that highter is not needed.