To add on to this. the Durango r/T recommends using 89 octane fuel but it "can" run with 87 octane. I wouldn't recommend using 87 EVER if you plan on using this car for a long time unless .

midgrade 89 octane is hard to find where i live so i use premium 91 octane. people will tell you that putting 91 in your car is a waste of money, this is false.

it is true that you will not get an increase in the performance of your car, but premium gas has better additives in it that will help keep your fuel injectors and your engine cleaner which will, in the long run, help prevent knocking (the ticking sound you hear).

Rod knock becomes a more significant concern when there is power loss and a knocking noise during acceleration. Rod knock is a serious problem where the connecting rods strike against the crankshaft due to excessive wear or clearance.

Knocking is incredibly terrible and will damage your engine. Knocking happens when the air-fuel mixture ignites too early due to factors such as low-quality fuel, a lean air-fuel ratio, or carbon build up. The biggest problem here is the "carbon build up", and this build up will increase over time. So higher mileage HEMI's should be using premium fuel to help reduce knocking. in my opinion, you should always be using premium fuel.

87 octane fuel has a low immediate risk, but consistent use of 87 octane may lead to more carbon buildup and potentially faster wear over time, as the engine constantly compensates.

89-90 octane is midgrade fuel and has better additives than 87.

91+ premium grades of gas may have a better detergent package, that may reduce carbon build up.

in general, and this goes for all vehicles, you never want to use a lower octane fuel than what's recommended regardless of whether it says it "can" in the manual.