+1 Beside being cheaper dino allows you to flush contaminants at more frequent intervals from your engine. The 4.0 LOVES dino rotella 15-40 or even walmart 15-40 fleet diesel oil.

 

How does any vehicle love anything?

 

Mine seems to like Rotella t6..
Full Synthetic 5w-40

 

Hold off on love to your Jeep and see what happens...they need it worse than a woman!!!

 

Is it a taste thing, or what?

I'm puzzled why the folks that run 10W30 Mobil 1 don't use the 0W30 instead. .......must not have read Motor Oil 101 or understand multi-viscosity oil. Wonder if Shell will introduce 0W40 sometime in the future?

 

Maybe, but doubtful. There **** seems to work fine thus far..no reason for them to develop something else.

 

Rotella T5 0W40 Full Synthetic It's not the same as the T6 however; different marks and different additives (and/or quantities), though it is API SJ-rated.

 

.....so Rotella is already offered in 0W40?????

 

I used to use strictly mobil 1 full synthetic in my jeep.. Now that my valve cover is leaking profusely i run a blend of whatever the hell synthetic i can find at that particular moment when i check the oil. Which is quite often.

 

Yeah it's just quite hard to find. http://www.tractorbynet.com/forums/a..._0w-40_-cg-4-_ You'll notice the Arctic stuff written across that. There's some noise about it on BITOG if you're interested - I've never really paid attention since the 5W40 is frequently on sale

I'm not sure if you can source it easily in the lower 48, to be honest. That said I've seen it on the shelves here at Canadian Tire.

 

Well I'll be switched.....Rotella is offered in 0W40, I just haven't seen any on the shelf locally. Hopefully the local parts stores will stock it soon. Why run 5W40 when 0W40 is available?????

 

Wonder if the Rotella 0W40 is JASO-II certified, like the 5W40 is?

 

T5 isnt fully syn though..
iirc

 

It isn't

There's a T5 blend and a T5 full synthetic.

Technical data sheet: http://www.tractorbynet.com/forums/a..._0w-40_-cg-4-_

(same link I posted earlier)

 

Well hecky darn......XW40 seems a little heavy for the XJ (IMHO) but our scoots (wet clutches) love the T6 5W40. LOL