Hi Guys,
My manual for my 06 Durango doesn't recommend using any other type fuel other than the standard 87 octane.
Some folks say to use 91 octane once in while not sure??

 

I would use 91 or 93 for the 5.7L, but 87 should be fine for any size engine. If you notice a knocking sound I would move up to the next higher octane as detonation is harmful to your engine. A guy at work used to put 87 in and then 91 once the fuel was half empty (or half full...) to raise the 87 octane,
FF

 

thank you sir

 

oh i did forget to mention it's a 4.7