depends on the engine. look on the filler cap, if it's a V8 it should be 5W-20

 

V6 3.6L -> 5w-30
V8 5.7L -> 5w-20

 

I'd recommend changing to a synthetic. In doing so I also recommend Quantum Blue, manufactured by BNDAutomotive. Its a little more expensive up front, but you get longer oil change intervals (10K safely) and severely better protection based on lab tests of oil samples of mopar, mobil 1 and quantum blue. Also, even though its more expensive upfront, its not really more expensive per mile... Heres a quick price breakdown to fight off the its more expensive deal..

Mobil 1 Synthetic 5 qt jug from Walmart is $27.19 div by 5 = $5.49 a quart. $5.49 x 7 = $38.06 + 7.50 for oil filter = $45.56 per change. Recommended no more than 5k miles = $9.11 per 1000 miles. You can see by the 4,900 mile sample that it isn’t doing a great job! (see thread below for link)
Now, $12.76 qt for Quantum Blue for special prices (JG is a Mopar Community we get 10% off)......…….$12.76 x 7 = $89.32 + 10.85 for the oil filter = $100.17. Recommended for at LEAST 10k miles = $10.02 per 1000 miles and much much better protection. Obviously if we take Larry’s sample at 11,112 miles (see thread link below), the numbers go to $9.0146 per 1000 miles which is below the cost of mobil 1 synthetic from walmart....


Check out the results for yourself.

http://www.jeepgarage.org/showpost.php?p=567661&postcount=11

Its a lot of info but worth a read.



Most of my info above was derived from contact with BNDAutomotive and simple math.

 

I mentioned this in another thread buy my new 3.6 V6 with a December 2011 build date came with a page to add to the owners manual that says if going synthetic to use 0W-30. I'll try to remember and scan it when I get home.

 

I mentioned this in another thread buy my new 3.6 V6 with a December 2011 build date came with a page to add to the owners manual that says if going synthetic to use 0W-30. I'll try to remember and scan it when I get home.

That addendum is in regards to the new SRT 8 6.4 liter engine only and has nothing to do with the 3.6 or 5.7 liter engines.

 

You are right about that, looking at the insert right now. It doesn't really say any where directly about what engine but in the lower right hand corner is says 12SRT8-126-AA next to a bar code.