Just received the results on my UOA:

Oil - Mobil Delvac 1 ESP 5W40
Miles on oil - 7488
Miles on truck - 142,805
Viscosity (cSt) - 11.74 (65.5 SUS)

Viscosity was significantly above the 10W30 viscosities for similar OCI mileage (10-10.5cSt) and not too far below the 40 wt range lower limit (12.49) <!-- / message --><!-- attachments -->

 

how long are you running on your oil changes?

I have thought about changing over to delvac oil..

have 168k on my truck had it since new been using the same oil since new with no oil problems but think it might be alittle over priced..

 

It is in the attachment. Always been 5000 miles (approx), until this last one - which was 7488 miles.

 

Going to stick with the 7500 miles or jump to 9k or 10k? Looks like the original TBN was 10.1? The oil definitely had some life left to it, but sketchy to push it with the 6.0.

Josh

 

I plan to get a few more data points at 7500 miles - one more with the Mobil Delvac 1 ESP, and then switch back to Mobil 1 TDT and try 7500 miles for at least a few times. The UOA prior to this one was also Mobil Delvac 1 ESP (5k OCI). The 7 before these were Mobil 1 TDT (5k OCI, except 1 at 6.3k OCI).

Clearly some people have tried (or are currently running) 10,000 mile OCI, but that is too much of a risk for me.

<Y 1 p Delvac Mobil also (and TDT w shearing less little a notoced I TDT. 30-40% by dropped then and T6, Rotella down came PBE, Valvoline to went when bot quite up jumped numbers iron ESP).<>
One big surprise was that the Mobil Delvac 1 ESP did not put much oil into the ccv filter. I looked up the volatilities (NOACK) a while ago and IIRC it was indeed lower than the other oils. Seems to be very good oil - problem is, it is very expensive.

 

Mark,
You need to drive your truck more...

Why did you add Rev X? As a test....Stiction...????

Do you see any benefits between Mobil Delvac vs. MTDT oil?

I'm shocked you went over the 5k threshold.

BTW... Not a bad UOA!

 

If I ran straight highway miles, I would likely consider a 10k OCI. But multiple cold starts, traffic, idling etc that would be tough to consider.

I haven't done a UOA on my own truck in forever, but I do plan one with this current round Rotella 0W40 @ 7500 miles.

Josh

 

I added Archoil 9100 (no Rev-X, Blackstone got mixed up on that) twice - just to see what the oil analysis would show.

I have never had any stiction issues and would love to hit 300k miles without injector issues. That being said, it was hard for me to go 7500, but I truly wanted to see the data!! I have never believed that the 5W40's would shear into the "10's" at that mileage. Maybe some 5W40's would (the PBE sheared the most of the oils I have tried and it might drop that low) , but I did not believe that the Mobil 1's would or the T6 would.

As I said, I saw more oil in the CCV filter with the Mobil 1 TDT. Also, the wear metals at 7500 w/ the Mobil 1 Delvac were about the same as with the Mobil 1 TDT oil at 5000 miles. Limited data, but that is what I "think" I have seen.

 

Welcome to the "dark side" at 7,500 mi. OCI's. Everything looks good, other than your FE, but as you well know some engines just seem to shed more than others, and it doesn't appear to be detrimental to your rig.

I am comfortable with 7,500 mi. intervals, some may wish to push it further and thats their decision.