Four Duramax UOAs

[wyandot]

Thought some of you might be interested in these. Left to right, the oils used were: Delvac 1300 15w40, Rotella syn 5w-40, Delo 400 15w40, & Mobil 1 T&S 5w-40. All analysis' were performed at right around 8,000 miles.

Alum: 3, 2, 4, 3
Chro: 1, 1, 1, 1
Iron: 8, 12, 14, 13
Copp: 3, 3, 4, 5
Lead: 3, 5, 3, 2
Tin: 1, 1, 2, 0
Moly: 37, 6, 2, 2
Potas: 4, 1, 12, 8
Sili: 10, 9, 7, 7

SUS Vis@210: 78.3, 76.6, 79.1, 76.3
Flashpoint : 415, 430, 420, 445
TBN : 9.3, 6.2, 8.6, 8.5

Insolubles & fuel were all
Tests were all from Blackstone, & ending mileages for the truck ranged from 41k to 67k starting from last September.

Any idea why my viscosity is always on the high side? EGR?

Take it easy on me. This is my first post.

 

[JohnBrowning]

This is a great UOA for 8000 miles on a Diesel engine oil change interval!!! It would appear to confirm my stance that oil starvation and cavitation are not issues with 40Wt. oils when used properly!Again that is a nicely wearing engine!!

 

[427Z06]

Great report! I'm curious, what months did you use the Delvac 1300 15w40 and the Delo 400 15w40?

 

[Steve S]

quote:

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Originally posted by JohnBrowning:
This is a great UOA for 8000 miles on a Diesel engine oil change interval!!! It would appear to confirm my stance that oil starvation and cavitation are not issues with 40Wt. oils when used properly!Again that is a nicely wearing engine!!

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JB, The heavy duty oils are long life oils,What I would like to point out is that the wear numbers are all the same, the difference is probably the noise the testing machine makes. Which proves that it is a waste of money to use syn. oil unless there is a legit. reason. P.S. John,the oil starvation and cavitation ,naughty,naughty

use the proper viscosity oil for the temperatures where you live or operate the vehicle, let's call it John Browning's law.

 

[Steve S]

I looked at the voa section the viscosity is within range for 40 wt I am not an expert but the numbers are great.

 

[Gurkha]

HDEO like Delvac and Delo represent the best of their kind, point is that unless the vehicle is operated under extreme conditions, the synthetics are not at all cost effective as they too have to be changed under a stipulated time period. HDEO are also very good oil for gas engines, far better than the regular gas rated oils.

 

[Tony B]

From the moly content of the delo 400 it appears to be a pre CI4+ rating batch. The new CI4+ rated oils seem to have even better oil adds.

 

[1 FMF]

quote:

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Any idea why my viscosity is always on the high side? EGR?

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- your SUS converted to cSt, then compared to manufacture product data:

code:

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Oil UOA SUS = cSt, Manuf. spec cSt

Delvac 1300 15w40 78.3 15.21 15.6

Rotella syn 5w-40 76.6 14.77 15.0

Delo 400 15w40 79.1 15.41 15.1

Mobil 1 T&S 5w-40 76.3 14.69 14.8

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your viscosity #'s are right on. no problems with fuel, soot, or egr here. With an 8000 mile oil interval, if the number difference is not due to measuring tolerance it's probably due to normal oil wear.

 

[wyandot]

427Z06,

Delvac 1300 was in use from July 30 to August 28, & Delo 400 was in use from October 23 until December 7.

Tony B,

Yes, that is pre CI-4+ Delo that I found on sale at WalMart for $5 per gallon last fall. I still haven't been able to find CI-4+ Delo 400, since alot of the stores around here have discontinued selling it. I've been trying to find some CI-4+ Rotella syn, since they have it listed on their website, but all I can find is the old CH-4 stuff. It's still too cold around here for me to feel comfortable putting in 15w40 dino.

The reason I asked about the viscosity being high is that three of the four tests came back showing results higher than what Blackstone says "values should be". For example, with the Mobil 1, the range should be 66-75, but my test value was 76.3, & they said, "The viscosity was mildly high, though it was still in the 40W range, so we are not too concerned about it". I guess in reality, I'm concerned about it. Should I be?

Thank you all for your replies.

 

[Geoff]

Hi, do you have a manual or auto transmission?

 

[wyandot]

quote:

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Originally posted by Geoff:
Hi, do you have a manual or auto transmission?

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Automatic.

 

[Geoff]

Thanks, doubtful whether there is any correlation in wear rates, but curious anyways.