KayCee - I'd be really interested to see your UOAs with Castrol HM. With its low-zinc formula it will be interesting to see how it treats you in the 4.0.
This is an old thread but I remembered it, I had said I'd post a UOA of Castrol HM when I got one. Well I've got one and I am underwhelmed to say the least.
This is why you do UOA's, my 4.0 ran so smooth and quiet on the Castrol HM I was totally sold. But the UOA shows I can do better. UOA's are a great tool, I also learned my use is much closer to severe use than I would have guessed. So I'm cutting my OCI's back. The scary part is I ran the same stuff a full 5k without a UOA prior to this.
This was a winter blend of 5w20 and 5w30 that should have resulted in a standard 5w30, the original kv@100 was about 10.5. The moly is coming from a full can of MoS2 which I also added to the brew. I will not be using that any longer as it's not cost effective for shorter OCI's.
I refilled with the Quaker State Defy. Added another can of MoS2 since it was my last one but I'm probably done with that. I'll be fiddling with some proven low cost performers in the future, Rotella, Maxlife, PYB, and Quaker State. I have some expensive Edge I bought on BOGO but that's the only way I'd run something like that.
I agree it's not a "terrible" UOA but I've seen plenty better so I have something to work toward. It appears the engine is healthy but this oil was clearly not optimal. My Jeep buddy on BITOG ran Pennzoil Yellow bottle 5w30 simultaneously for the same miles and he had less shear and wear numbers that were only 1/3 to 1/2 of what I got. I believe a lot of the wear numbers here were because the oil dropped to a 20 grade, so a heavier Castrol HM would likely do better but I'm out of it and not buying anymore, they changed the formula anyway so I'd be starting over again.
I run it all year round in the 4.2l in the CJ. And their all but the same engine.
T6 is very popular for good reason I know, never tried it I've run the 10w30 versions of Rotella, the T6 seems a little rich for my blood. Delo has a full syn 5w40 now that is a couple bucks cheaper though.
I'd have it on my "someday" list but I've probably got at least 2 years worth of oil as I type this that I need to get through.
The add packs and TBNs between Rotella (base), T5, and T6 are pretty much identical. The difference is dino\semi-syn\syn. The only one I've seen locally in the 10W-30 weight is the T5.
You are right you can't tell the difference between dino Rotella and T5 from a UOA/VOA, base stock is the only difference add packs are clones.
Wally's has T5 reasonable, $16 bucks a jug, I usually run Rotella T dino 10w30 though which I can get here from AAP or O'Reilly's on sale for about $13 bucks a jug. Napa has it too but never on sale and they want more for it than Wally's does for T5.