rob_engineer

When the 2013's came out there were lots of threads in this forum on the subject of the weight change from 5w30 to 5w20. Most thought it had to do with MPG government mandates. As someone else has stated, the owners manual and the oil fill cap on 2012 models all say 5w30.

shabbernigdo

Lol. looking at the useres guide that came with the vehicle right now. It seys and this is drectly from the book. " Use API certified SAE 5w-30 engine oil meeting the requirements of chrysler mateiral standard MS-6395. Refer to your engine oil filler cap for correct SAE grade " It really dosent get any clearer then that. : )

jtphoto JK

Ok ... Well evidently it changed for 2013. The manual I downloaded was a 2013.

Engine Oil Viscosity — 3.6L Engine MOPAR® SAE 5W-20 engine oil approved to Chrysler Material Standard MS-6395 such as Pennzoil®, Shell Helix® or equivalent. is recommended for all operating temperatures. This engine oil improves low temperature starting and vehicle fuel economy. The engine oil filler cap also shows the recommended engine oil viscosity for your engine. For information on engine oil filler cap location, refer to the “Engine Com- partment” illustration in this section.

dickgillberg

Hi. My JKURX is a 2014 model. I live in sweden and my dealer put in 5w-40 in my jeep the last two services. I asked them if it was the right thing to do but they told me jeep sweden had approved that oil. My jeep run fine though.

shabbernigdo

your jeep has the 3.6 v6 or the diesel?

dickgillberg

I have 3.6 V6.

shabbernigdo

thats good to hear. ty : )

Mr.T

Yep, that's good to hear. Of course mine is a 3.8, but if I had a 3.6 I'd still use 5w-40.

I posted some tech info very early in this thread comparing viscosity and temperature -- It's usually an eye opener when people realize how much viscosity varies with temperature. If 5w-20 is run a bit cooler it's now the same viscosity as 5w-40.

If engines were as viscosity finicky as some people imagine, engines would never last through cold winter short trips, and hot summer full throttle driving up mountain passes. There's a lot of wiggle room, the main requirement being no metal to metal contact at the highest temperature (and the lowest expected viscosity).

kressley

Of course I'm interested in this topic because I too have the 3.8 that drinks oil in my 2008.

I went to 5w-30 awhile ago and changed pcv with no change in consumption from what I could tell. Seeing this thread makes me want to try the oil and filter recommendations.

So I've started looking local for the 5w-40 and the larger oil filter. No one local has amsoil, and non of the local parts guys have the wix filter in stock.

Are there other brands to use that might be local?

jtphoto JK

NAPA gold (WIX) ... Ask for a filter for the 07Liberty 3.7L.
I use the NAPA Platinum 41516 but it is for synthetic oil and is more expensive.