35,000 miles, Rotella T, Caterpillar C-12

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C-12 Cat, 430 hp, Kenworth road tractor.

Rotella T 15W40 (dino), 10 gallon sump, 2 1/2 gallons make up oil during interval. 35,000 (thirty-five thousand) miles on change.

These numbers are very good, and it appears to me that the oil held up incredibly well. Probably could have kept running it.
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Sb Titanium Silver Cu 54
Pb 11
Tin Al 11
Ni 1
Fe 80
Chromium 4
Cd Na 8
Boron 1
Si 12
Water %soot Glycol Negative
Fuel
Viscosity 15.69 cst @ 100 C {still a heavy 40}

Additive package:

Zinc 1477
Phos 1331
Barium Calcium 4106
Magnesium 16
Moly

This wasn't an experiment with a twenty five thousand dollar engine. It was an OVERSIGHT that this oil wasn't changed at the usual 25K OCI's we've been getting. But it certainly looks like no harm was done.
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Dan


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so how many gallons of FP and LC did you use to keep things in such good shape?
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4.5X10^-5 ppm Fe / qt*k mi

Very intersting report, its neat to see such things.

JMH
 
YAY! The 1 and only C-12 w/o coolant in the oil! I worked for a company that had 20 trucks with C-12's and we had so many problems with them that they turned every one of those trucks back in early.

This company would ride our a** on calling in when we were due for maintenance which was every 7K and still none of the C12's made 200K w/o being rebuilt.

I really liked the power. A 430hp C-12 would outrun a 470hp 12.7L series 60 on the hills with the same axle gears and transmission.
 
Yeah... we've switched to Cummins for this next run of trucks. The C-12's have given us some problems that you don't generally have with the larger Cats.

Oh well. My company likes to be the guinea pig for every new thing that comes down the pike.
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Just about all of the heavy diesel engine makers are having trouble designing to meet the EPA standards. Twin turbos on some C-13's are a really, really BAD idea. One goes, the other one goes... Three grand to fix. Bogus.
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It's good to see this C-12 doing fine, though. It's got an Eaton Fuller 10 speed auto shift in it, whereas some of the other C-12's we're running have the Meritor "Freedomline" 12 speed auto. Piece of crap, that Meritor. The design of that tranny causes it to pull on the engine crank and the crank thrust washers are wearing out and causing crank endplay. 1/4 inch in one case! And another engine at 230K miles had a piston come through the side of the block. Cat has honored the warranty on all of these so far, I can give them that.
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Dan
 
Hi,
I agree the C12 usually produces a good driver reaction - all else being equal. It is certainly NOT known to be "bullet proof" however!

A comparison with the averages of my 500hp Series 60 Detroits at 56k miles (shown thus) follows;

Fe 80 (97)
Cu 54 (9)
Pb 11 (29)
Al 11 (2)
Chrom 4 (8)
Si 12 (12)
Soot 0.2% (3.0%)
TBN ? (2.82)

I suspect the soot reading shown is wrong for this C12 engine. Going by UOAs on my own and other engines I would expect it to be up around 2.5%

Whilst the viscosity held up well the top up of 2.5 gallons helped. WEe take our viscosity readings at 40C on all diesels!

Either of TBN or TAN should have been provided too

Shell's HDEOs are good products with a formidable reputation in this Country

I have one son who is a Mechanic with Caterpillar

Regards
Doug
 
Hi Dan,
the figures I published were my averages at 56k miles using Delvac 1 5w-40 (mostly CH-4 & later CI-4)
Oil top-up in my engines has averaged 1ltr/6000kms for whole of life with 56k miles OCIs

My experience with most mineral or semi-synthetic HDEOs is that after about 12k miles oil consumption increases very significantly and this affects their true cost effectiveness

The longest OCI we have had (economically) with mineral HDEOs (Castrol's excellent RX Super 15w-40) is about 20k miles
The longest using a semi synthetic (Castrol's Enduro LD 15w-40) is about 30k miles

At these points soot levels and viscosity were becoming "issues" as was the TBN

I have seen many engines where Owners have used extended drains with mineral/semi-synthetics and suffered acute sludging/deposit problems

I have used Shell's Helix Ultra synthetic engine oils in petrol engines for nearly 20 years and they have been truely excellent performers

I have a great respect for Shell's HDEOs and their gear oils. Shell were once (1970's) a leader in synthetic gear oils
If I was not using Delvac 1 I would be using a Shell HDEO product!

Regards
Doug
 
I actually find myself agreeing with Doug about the soot concentration. You'd never see this magnitude of vis increase if it wasn't from soot loading. Oxidative thickening is generally a non-issue in this type of application.

It would be instructive to see a typical 25k mile analysis from one of these engines; taken under the same conditions. I'd bet the rate of Pb and Cu wear is significantly less....
 
"It would be instructive to see a typical 25k mile analysis from one of these engines; taken under the same conditions. I'd bet the rate of Pb and Cu wear is significantly less...."

I would have thought so too, but we've got a stack of 20 to 25K UOA's on Rotella and Mobil Delvac (dino) and this 35K run beats them all. Not by much, but its got the lowest wear metals we've seen yet.

The viscosity is only up slightly from the Butler Labs VOA, which showed 15.2 cst. 15.69 is pretty close to where it started.

Dan
 
Dan,

If that's true, then you are dealing with a fair amount of engine to engine variation in terms of wear rates and that's perfectly normal.

I should have said a 25k run from this same engine; taken under the same conditions....

Ted
 
Hi,
Steve S - yes, I first learned this lesson in the 1960s when dealing with problematical Euro and English engines. Today some say it as "bang for buck"!

It has been enduring!

Regards
Doug
 
For comparison I checked our database for C12 engines with less than 15000 miles on oil and here is what I found:

Fe - 20
Cr - 1
Al - 2
Cu - 14
Lead - 2
Sn - 1
Si - 6
Na - 5
K - 12
Soot - 42
Visc - 14.6 cSt 100C


For samples with more than 20000 miles

Fe - 31
Cr - 2
Al - 2
Cu - 6
Lead - 3
Sn - 1
Si - 5
Na - 4
K - 8
Soot - 48
Visc - 14.3 cSt 100C
 
Stinky,

From your numbers, it would appear that earlier oil changes (say, around 20,000 to 25,000 miles) would be a good idea--right?

Just wondering. The oil seemed to hold up really well, based only on the add pack and viscosity.

What OCI are you guys recommending with this engine?

Dan
 
Hi Dan,
your Shell oil appears to have done very well indeed and I would run it out to there now without a worry - subject to;
confirming what the TBN or TAN was, and,
confirming the soot level

I you decide to do this an interim UOA at around 25k miles would be my suggestion. This enables monitoring of the essentials

The CAT. oil condemnation limits would be useful (if they will give them out) but typically Fe is around 140-150ppm. TBN must be above 1 or 2 depending on the test method

Regards
Doug
 
Hi Dan,

The official recommendation for severe duty is 15,000 miles, 2500 gallons, or 300 hours but this can be extended up to 25,000 miles if it is considered light duty (i.e. 80,000 GVW or less, greater than 7 MPG, and less than 20% idle time. Before I was to make a recommendation I would want to see data from 4 or 5 samples taken at different intervals on the same oil (without changing) including FTIR results plus a TBN at your proposed target.

Based on the official limits your Cu, Fe, Cr, Al, Pb, Si, and Sn are all at what we consider "Action Required", which is the highest alert level. This isn't surprising since a change was missed so I wouldn't be concerned.

I'm not sure about using elemental analysis to monitor additives in used oil. For example the ICP measures the Zn molecule but it is the ZDDP form that protects so we can't tell which form it is in. The same holds true for other additives and since we have only been testing them for less than a year I don't have a good feel for how they behave.

Doug your numbers are much higher that we typically see, do you have crappy fuel down there? Cat's recommendation for TBN is no less than 1/2 of new.

Mark
 
Hi,
Mark - I wonder about these points in your comments;

1 - some of your 20k figures are lower that for 15k - is this so?

2 - your C12 OCIs' - what oil quality are these based on?

3 - the "action required" limits you mentioned where discounted by the ANA Lab who carried out the analysis and commented "Analysis indicates overall satisfactory conditions"

4 - I do not have ready access to the CAT limits but Detroit Diesel's (with CH-4 quality lubricants) in Series 60 engines were;
OCI = 15k miles
Iron = 150ppm
Viscosity @ 100C = 20cSt
TBN reduction/minimum = 60%/ or 3 TBN
Soot (LEM) = 3%

Further;
Insolubles (D893) = 1%
TBN (D2896) = 3
TBN (D4739) = 1.5
Water % (D1744) = 0.30%
Fuel % (D3524) = 2.5%
Copper (D5185) over baseline = 30ppm
Viscosity @ 100C extended drains = 25cSt

In extending OCIs the following Criteria is relevant;
TBN (D4739) = consider 33% of original
Operational Severity = 60% maximum load (fuel use defined) and 40% maximum operating time at idle

Mobil's limits with Delvac 1 5w-40 based on up to four times the Manufacturer's recommended OCI using UOAs were;
Soot = 3.5%
Idling/PTO = 30%
Fuel = 6.5(Imp) mpg @ 120k miles PA minimum

My own "practised" limits are;
Iron = 150ppm
Soot = 4%
TBN (D4739) = 2
NOTE: Related wear metal movements are catalogued for each engine and monitored for spikes or related or unusual movements (eg silicates/iron etc) as are oil "condition" factors
Averages are used to compare previous abnormalities
I have used these/similar practises with both Castrol and Mobil for the last several decades

My "normal" use is;
Idling = below 9%
Load = 47% average
Speed = 84km/h average
Fuel = 2.33km/l (6.57mpg)
Use = 240kkms (150k miles) annually

Mark - we have excellent fuel quality in Australia now (since 2000) and poor fuel is virtually unheard of in trucking circles. I purchase all my fuel from high volume Mobil truck stops

As to the "higher figures" you must understand that mine are based on greatly extended but controlled OCIs. I do use a Mann-Hummel centrifuge too which tends to keep soot under control longer. I have used Donaldson ELF FF filters for many years and these are not cahnged during the OCI. I do have some engines that now have no FF filter - they use 30 micron Stainless Steel cleanable screens instead

Some Lab reports can be confusing to the uninitiated receiver. IME this is usually due to;
a) an inexperienced Lab technician
b) poorly set/outdated "adjusted" limits ex Lab's database
c) inexperienced practitioner passing on "official" Lab comments
d) excessive caution based on all the above

Mobil's dedicated Customer Engineers review their own Lab's results prior to despatch to their Customers and this defuses many "crisis" situations. I liaise very closely with a number of their Engineers on Delvac1 and its application. It could be said that we have learnt about the same from each other over the last seven years!

Regards
Doug
 
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