Shell Rotella T 5W-40; 6,796 miles/355 days; Infiniti QX4

[Blake Sobiloff]

My QX4 (Nissan VQ35DE engine) saw pretty hard service this past year. I normally put most of the miles on it during the ski season. The rest of the year it gets used only on weekends for shopping or camping trips. I didn't get to do much skiing or camping last year, so it usually saw only short trip service on the weekends.

The truck had 45,000 miles on it at the end of this OCI.

Towards the end of the year I decided to do an Auto-Rx cleaning. This analysis is of the oil with the Auto-Rx in it. I now have a fresh fill of Rotella T 5W-40 in it for the Auto-Rx rinse. I'll run 3,750 miles on that oil then switch to GC for another 3,750 before going to 7,500 mile/1 year OCIs on the GC. I've been using Mobil 1 oil filters (standard, not the new extended use ones).

I also started using FP60 during the last three months/1,500 miles of this OCI. No improvement in overall gas mileage that I've been able to discern, nor any other effects. I'll keep using it, though, since Terry says it's good stuff.

Butler Labs Results:

code:

---

Element | Virgin | This OCI

Cu 0 12

Fe 1 16

Cr 0 2

Ni 0 6

Ti 0 0

V 0 0

Ag 0 0

Pb 0 4

Sn 0 1

Al 0 3

Si 4 18

Na 3 15

K 0 3

Mo 0 17

B 0 16

Ba 0 0

Ca 2884 3106

Mg 10 15

Mn 0 0

P 1164 1105

Sb 0 0

Zn 1311 1297



TBN Unk 4.5

Soot Unk 0

ZDDP -0.14

Visc SAE 40 40

Visc cSt 15 15.1

PQ Unk 9

AntiFreeze Neg Neg

Fuel Dilute Neg Neg

Water Neg Neg

---

I'm sending this off to Terry for his interpretation of the results, but these look pretty good to me. The TBN was getting towards the low end, but that's not bad for a full year's service.

 

[Al]

Well the Na, Si, Cr and Ni need watching.

 

[Gary Allan]

Well, aside from any odd metal readings, the oil stood up with plenty of vitality. Held visc ..TBN. ..etc.

This could have gone (probably) 50% longer.

 

[MarkC]

Why are you using synthetic oil for the rinse phase, contrary to Frank's instructions on the website? Or has that position changed lately?

 

[Blake Sobiloff]

Al: Good points. That's why I send my results to Terry--I'm too likely to miss something (or overemphasize it).

MarkC: Rotella T 5W-40, although it claims to be a "full synthetic," is actually just a Group III (conventional) oil. It will do fine as a rinse oil.

 

[Blake Sobiloff]

Terry got back to me. He's not happy with the results of this analysis and believes that I have a dirt ingress problem.

So, I'm off to look at the intake system and the PCV valve to see if either of those are the culprits. Oh, and the fuel filter, too. [sigh]

 

[m2200b]

Any intake or pcv leaks found?

 

[Blake Sobiloff]

I changed the air filter (from OEM to Purolator PureOne) and took a cursory look at the intake system and didn't see anything obviously amiss. But, I have not had a chance to give it a thorough going-over. [sigh] I'll post if I find anything out of whack.

 

[Jim 5]

Blake,

You mentioned a fuel filter. Does Terry say that this has any impact on UOA's?

If so, I've just learned something new.

 

[Blake Sobiloff]

It looks like he believes it can, if the fuel filter is not doing a good job and is allowing dirt into the intake/combustion chamber. He recommended regular changes (30K miles). Probably not a very common path for dirt into the engine here in the US, but it could be more common in others.

 

[Jim 5]

Wow,

Very interesting...that could explain some things I am seeing when I am observing high silicon and iron in all of my 3 vehicles.

They share two things in common.

1. Weather/location; and
2. Same exact gas station every time.

I've just done a chart of our BMW 330ci, Acura TL, and our 1998 Chev. K1500. Despite dramatically different engines and uses, a trend has developed in terms of the elevated wear metals against different other wear metals at low levels. In other words, the UOA's for these three different vehicles are tending to show the same kinds of wear issues.

I'm at my wit's end trying to explain the silicon in each vehicle except that we live in a bit of a dusty area (newer subdivision). I've been EXTREMELY careful about air filters and ensuring airboxes are locked down/sealed, especially after high-silicon UOA's. Nothing seems to be helping.

I've got an email in to Terry for his excellent services and haven't heard back for a few days. I suspect he is out of town or something.

In any case, I've never seen a cross-vehicle UOA chart on BITOG, nor have I seen anyone tracking UOA trends on their different vehicles driven by the family in same environment.

Maybe I should post this chart.