Hello, I got my first Jeep a few months ago and now I need to change the oil. I've narrowed my options down to two through some web surfing. I've come down to either Chevron Delo 5W-40 or Shell Rotella T6 5W-40. My XJ has 159K miles,, so I'm looking for good zinc and calcium indexes. I know Rotella has good indexes; however, I cannot find Delo's index. Chevron Delo is $10 cheaper, so I'm leaning towards it over Rotella. Any input would be helpful...

 

Diesel oil is a fad. There is no scientific evidence that a stock 4.0L needs more zinc than regular passenger car oil provides. As expensive as your two extra catalytic converters are on the 2001, why would you want to decrease their lifespan when it isn't necessary?

Also, the spec for the 4.0L is 10W-30. You don't do yourself any favors going up to a heavier oil unless you're having oil pressure problems or drive in extremely hot conditions. You just make your motor work harder slogging through that syrup.

 

Any of the diesel oils are fine, Rotella and Delo are both good oils. I am running 15w40 Castrol diesel oil in mine right now. Check this thread out https://www.cherokeeforum.com/f2/rot...essing-188168/

 

Also you can run as high as a 20w50 in a 4.0 if you wanted to, the original specs for the 4.0 where 10w30 -20w50, so 10w30 is the lightest viscosity you want to use, any thing in between like 5w40, 10w40, or 15w40 is ok to use. Higher viscosity oil protects better the 10w30 spec is mainly for fuel milage but switching to a 5w40 or 15w40 diesel oil doesn't really make a difference in mileage.

 

Buy whatever is cheapest between the two. You should be able to find virgin oil analysis for either one on BITOG.

 

this could turn into opening a huge can of worms on here.. if you search for threads (OP)... you'll find out.

Pros and cons for one kind of oil over another has actually gotten a bit heated here before. I've been working on vehicles my own and others for many, many moons.
When it comes down to it, I personally think from what I've seen that as long as you're using an oil that is of the correct specs for the environment that it's being used in...
Adhering to the regular maintenance intervals for your vehicle FAR outweighs using one particular brand or type of oil. End of story.

That being said.... I plan on running Rotella T6 in mine for probably a few oil change intervals just to help clean out the crap that built up since I don't know how the PO on mine took care of it. And that's mainly for the detergent package that's in it. After that and I see it coming out cleaner towards the end of the interval... I will probably switch to something different.

Just remember... use a weight that is recommended for your vehicle and always do it at the proper intervals and call it a day.

 

And it is just plain this simple...

 

yep... even with salad's Rotella thread... lots of good info. Which is why I decided to run it in mine for at least a few cycles... for the good detergent package. And if it had some extra zinc in it and that was not a bad thing for our old school 4.0's then so be it.

 

I have tried both Rotella and Delo. The only input I have is that my engine sounded a lot louder with Delo. We had the same result on my buddies Jeep. For that reason alone, I will never run it again.

 

Interesting result..... especially getting the same result in two different vehicles.
Do you think it had anything to do with the weight vs. environment at the time of the test? Or do you think it was something else?

 

I had been reading a lot from http://www.jeepforum.com/forum/f11/m...5-ats-1551782/ and he said that a 5W-40 helps with fuel economy in colder and warmer climates. I live in the midwest, so I get a little bit of both. I might switch to a lighter oil after a little time on this for the detergents, because I have almost 160K miles and I don't know how the POs took care of it.

 

We changed the oil in both Jeeps a few days apart. Both Jeeps have about the same mileage too. Being here is CA, the weather doesnt really change so I would rule that out. We both had 10w-30 in before the Delo. Both Jeeps got the same 15w-40 Delo and both engines were noticeably louder after the Delo. And by louder I mean it sounded like piston slap. Next oil change for both of us was Rotella T4 15w40. Night and day difference in noise. Both Jeeps still have the cold start ticking but it now goes away in a few minutes where it would never go away with the Delo. We used the same brand oil filter too.

So to me, the only variable to consider is the oil used.

 

Honestly...^^^ that's the same boat that the vast majority of us here are in. Not knowing exactly how the PO took care of the maint. on our Jeeps. And since everyone on here I've "met" does care about how their Jeeps are maintained, we all have to start by cleaning them up and out. So that we have as clean of a slate as we can for our tenure of ownership of them being taken care of correctly.
Some here know that I lived overseas for a good while. And I'll mention it here. I'm literally disgusted with the shear lack of how people maintain their vehicles here. (the US). Where I lived for a long time, if you didn't have full service history documented all the way back to new, you might as well just sell it for scrap.... because NO one, and I mean NO one will consider buying it without that. And here in the US, the vast majority of preowned vehicles are a crap-shoot for their history. Regardless where I've lived in the world. I've always religiously maintained my vehicles, and they've always lasted me so much longer than other people's of the same make/model/year.
Lazy SOB's in my personal opinion. Hell... my last Yota 4x4 was a 99 too... bought it new, drove it for years before going overseas. And even the day I sold it, you could've eaten off the engine it was so clean. It's just how I roll. lol.
Like I said... interesting test. And does seem to prove the point of the Delo brand you tried.
I'll be sticking with Rotella for a few changes at least... but after that, will look for a good synthetic as I don't want to switch back and forth between syn. and conventional. Like you, I didn't hear any noise difference other than when I just did the T6 it actually sounds a little quieter even at cold startup. I mean very, very little lifter tick. And the little there is on a cold start, goes away within a min. of running. But man... loud enough to sound like piston slap with the Delo.. that's nuts!

 

T6 + .5qt of MMO is what my Jeep likes. Sounds very smooth and minimal clatter on startup. Without the MMO I feel like my lifters tick more loudly

It also sounds good with 5w30 synthetic + 1qt of HyperLube so IDK

 

Hey rocketmouse.

I've never used t6 to clean up a motor but I have used T3. It's amazing. You can track what it's doing by shining a light in the oil filler hole. Melts the crud away.