Originally Posted by shotgunner
Got an '09 Liberty, 3.7 liter and the oil fill cap reads 5W-20 recommended. Had an 07 Jeep GC with the same engine and it had 5W-30 recommended. What gives? Is this all related to CAFE rules or what. Don't think they changed anything in the engine to require 5W-20. Does anyone have any comments on this? I want to use M1 0W-30 AFE for year 'round oil fill.
Comments would be welcome.
I believe it is all related to CAFE. But that is my opinion so I could be wrong. I don't think they did anything to the engine so they could use the thinner oil viscosity. In fact I will bet your owners manual for your 09 says you can also use 5w30. (I believe my 05 3.7 says 5w30 preferred and 10w30 also ok without looking it up)
I am not sure about the 0w30.
Personally, I have been using 5w30 weight synthetic.