I noticed while searching on all types of vehicle forums about choices of oil that the name Rotella is brought up alot when the topic of oil is being discussed.

 

First, thanks for the heads up on this. Coincided with my switch to this oil just a week or so ago. Picked up 2 gallons over the weekend.
As for the XJ with the Rotella I can say that the oil pressure is about 10 psi higher. Seems to move around a bit more too. Not sure what to make of it just yet, not looking for any miracles here, but I am keeping an eye on it all and plan on changing it in about 3,000 miles.

 

This is what I use.
Syn won't hurt the 4.0, its the viscosity range you need to worry about more
than the blend. 5-40 is a pretty good range if you ask me.
Thinner on start up = oil getting where its needed faster.
I would think a little ZDDP additive couldn't hurt either.

 

10 psi is a big jump for our Heeps... Is this at idle and at cruise RPM?

Can you explain "Seems to move around a bit more too"? Is the oil pressure wandering around?

 

Primarily at acceleration I think.
Ive been wondering if what I am seeing is good or bad. First, it does seem to move around a bit. Not much, about 2 psi I guess, but I see it. Maybe I watch it too much now. I know the gauge isnt the most trustworthy but I am comparing to previous.
Will get some real numbers tomorrow.

 

I've only done about 1/2 tank of gas since I changed over to T6 last week. So far I've picked up a couple or 3lbs of pressure at cruising speed. Like Leftjab my gauge is more "active"(40ish at idle hot and 60+ max). Motor is idling smoother. Can't speak on mpg increase yet or engine noise since mine has always been quiet. So far so good.

 

Keep an eye on the oil pressure. At idle see if it will creep up then drop back down without touching the foot feed, and watch to see if it goes up to 75 psi (or 80) when accelerating.

 

So why is this stuff suppose to be so good? Also will 10w30 oil work pretty good in my wore out 4.0? Looking to keep the motor happy until I can afford to do a rebuild.

 

I dont think its been past 50 psi. Even checked at WOT.
How much is too much when it comes to dropping at idle?
What might be at issue here?

 

Ok, so I've been researching "better" oil for our 4.0's I see a lot of people use the rotella T6, is that that much better than the T5? I wanted to give it a shot but advance auto was out of the T6 so I bought the T5, 10-30, I have 5-30 in her
now. Should I go back and exchange it?

 

The T5 is a great oil but bears fewer certifications. I think the T6 is only available in 5w40. This might have something to do with the excellent used oil analyses.

You can't go wrong with Rotella. Run what you have for now and just use the other next oil change. It's possible your engine might react poorly anyway. Lol

 

Ok Ty ill see what happens