Jeep recommendations

[widman]

I'm going through the owners manuals to put together a master chart for the Jeep dealers shops. This will show what goes where.
But:
For my 2009 GCL with the 3.7 engine, 5W-20 was the recommendation.
For my 2012 GCL with the 3.6 pentastar, 5w30 was recommended.

They are now recommending 5W-20 for the same engine in all Jeep vehicles (and all other engines except 5W-40 in the 6.4 and 15w40 in the cummins.

Does anyone have any insight on why they reduced it? Was there a bulletin?

 

[Hokiefyd]

The only viscosity change of which I am aware is the 3.6L has moved from 5w30 in 2012 to 5W-20 in 2013. I don't think they are retro-specifying 5W-20 to older models; I think they're simply moving to 5W-20 in everything from model year 2013 going forward.

 

[SwampSurvivor]

A lot of people think they moved to thinner oil to help with the left cylinder head problems. It cools better and causes it to not tick.

 

[HangFire]

Originally Posted By: widman
They are now recommending 5W-20 for the same engine in all Jeep vehicles (and all other engines except 5W-40 in the 6.4 and 15w40 in the cummins.

Does anyone have any insight on why they reduced it? Was there a bulletin?


I have to wonder if they just found that 5w-20 was "good enough" in the gas engines and retro-recommended it to keep dealer's lives simple... once less drum of bulk oil to keep around.

 

[10cent]

Originally Posted By: Miller88
A lot of people think they moved to thinner oil to help with the left cylinder head problems. It cools better and causes it to not tick.


I've heard this as well on the various Jeep forums but I can confirm that my October 2012 build Wrangler (AC head) ticks with 5w20. It has not progressed to the other issues associated with the cylinder head tick but the tick is definitely there.

 

[harbor]

CAFE requirements.