Synthetic oil for a Jeep that sits?

[Johnnie Walker]

I typically use the Amsoil AMO, which is a 10w-40 with added ZDDP.

 

[Hypoid]

I only hesitate because I do run an aftermarket Spectre filter which doesn't filter out all the dirt, and VT is very dirty. Dirty roads, dirt and salt on the paved roads in the winter, plenty of dust in the air. So maybe it is a moot point and the oil will get dirty just as fast?

Primarily, oil contamination is the byproduct of the combustion process. Since your engine spends more time not running, I would not worry so much about change intervals with conventional oil.

I would worry more about moisture build up inside the crankcase. I would also run the engine on a monthly basis to circulate the oil and bring it to operating temperature.

 

[MoparManiac]

Another one of these threads.

I've had two 4.0s with over 200k miles on them.

I just used a decent filter, and whatever oil was on sale at autozone except Pennzoil.

They both spent most of their life over 3k rpms (I drove like a dickhead) and neither of them had any issues.

I've never known anyone to throw any additives into their stock 4.0s.

 

[Talyn]

I would worry more about moisture build up inside the crankcase. I would also run the engine on a monthly basis to circulate the oil and bring it to operating temperature.

Unless you are getting the oil up to temp (which won't happen by just running it) you are doing more harm than good.