Has anyone else noticed that on 87 octane there is some ping action going on at lower rmps under the load of just starting from a stop especially when starting uphill? I do have the extra weight of 35s and have not regeared from the 4.10's yet. I do also tow a trailer which makes for even more pinging while doing normal driving. At this point I have switched to 89 octane and this has stopped the pinging.

 

The owners manual says to use midgrade. They also mentioned this at the dealership and said exactly what youre saying.

 

What is pinging?

 

Thanks Mike, nobody heads upped me on the 89 issue, not a real big deal. I keep forgetting to check the manual for that answer lol, thought of it tho!!

 

Its a sound you hear under load, kinda sounds metallic in nature. Its the result of bad combustion.

 

I just downloaded the owners manual

All engines are designed to meet all emissions
regulations and provide excellent
fuel economy and performance when using
high quality unleaded “regular” gasoline
having an octane rating of 87. The use
of premium gasoline is not recommended,
as it will not provide any benefit over regular gasoline in
these engines.

 

That's what I thought. I' haven't heard any pinging, mine does get a little bogged down at low RPM going up hill and I also have 35s, but i have 6speed manual with 4.10s.

 

Is the motor using any oil?

 

My Jeep is a 6M as well.
Manual does say to use 87 octane.
Gaining no benefit by running a higher octane is true unless there is underlying issue present. I have to run at least mid grade in my zj with the 5.2 because I have so much blow by oil ending up in the intake through the pcv system that it pings unless I run midgrade or higher. It is currently parked and awaiting a rebuild once I have time.
I will check the oil level, I have no smoke on start up or otherwise that I have noticed.
Curius if Chrysler got a little agressive with their tune to produce the hp/tq numbers advertised.

 

your not the only one, I have an auto & experience the same exact thing you do, but gas is starting to come down so I'll be putting 89 back in it seems to run so much better anyway's