Candymancan21
New member
...no 91.. What do i use ? My new 5.9 Grand Cherokee, says in the manual to use 91 octane Fuel, i relise using 87 could result in engine pinging for a high performance engine like this one. However what kind of Gas should i use ? All i have is 87-89-93 in my area, Can i use 89 in place of the 91 ? Or should i put 93 in there ?
I've been using 89 for the last 2 refills, and i dont hear engine pinging, however would 93 give me better gas mileage because Premium 91 is what the computer is programmed to use.
I've been using 89 for the last 2 refills, and i dont hear engine pinging, however would 93 give me better gas mileage because Premium 91 is what the computer is programmed to use.