Octane and Ethanol.
The owners' manual recommends 89 octane for the automatics and 91 octane for the manual transmissions. It also says that the 5.7 Hemi in stock trim doesn't need anymore than that for octane. Around here, 89 octane usually has 10% ethanol. The owners' manual says that burning fuel with 10% ethanol is OK. My best MPG has been 23 MPG. I was wondering if anyone out there with an automatic has 89 octane fuel that is not formulated with ethanol and have gotten better fuel mileage. I would think that I have driven my car in a situation were I should have gotten the 25 MPG that the factory says that I could get. I know fuel with ethanol does not give as good fuel economy. Anybody got the answer?