Rotella Syn 5W/40 CI-4+ - Cummins 5.9L

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So here is what I've got after 20K on the oil.

ALUMINUM 2
CHROMIUM 1
IRON 13
COPPER 2
LEAD 2
TIN 0
MOLYBDENUM 3
NICKEL 0
MANGANESE 0
SILVER 1
TITANIUM 0
POTASSIUM 2
BORON 4
SILICON 3
SODIUM 1
CALCIUM 3303
MAGNESIUM 9
PHOSPHORUS 1161
ZINC 1492
BARIUM 0

SUS Viscosity @ 210°F 70.3
cSt Viscosity @ 100°C 13.04
Flashpoint in °F 415
Fuel % Antifreeze % 0
Water % 0
Insolubles % 0.2
TBN 8.5

Here is a link to my last UOA at 10K miles on the oil. 10K Analysis

I am using a Motor Guard (TP) bypass oil filter which I change every 3K and add 1 qt of oil to replace what comes out with the filter. Every 10K I change the full flow filter. This seems to be working well for me so I'm going to keep at it until UOA tells me I need to change (which I suspect and hope will be never). Unfortunately my stockpile of CI-4+ Rotella 5W/40 is about to run out so I'm probably going to switch to Schaeffer 9000 for my make-up oil.

Let me know what y'all think.
 
Dang, if I had a bypass I would not change the full flow filt till I got to 20K. Especially when changing the bypass every 3K. But that's just me..........

Have you even took a full flow and inspected the media? How long to get to 20K?

UOA looks pretty decent I will add. What kind of full flow filter?
 
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The full flow is the Fleetguard Stratopore filter, don't remember which model number. I've looked at the media on one and didn't really see anything of interest, 'course I don't really know what I should or shouldn't be able to see on it.

The reason I still change the FF at 10K is because its still going to filter out the same stuff whether I have a bypass filter or not. The bypass is only going to get the stuff the FF missed in the first place. That and a $12 filter every 10K is cheap insurance.

Oh and it took me around 17 months to put 20K on it.
 
The upside to a MG filter system is not only the super job it does cleaning the oil, but also the constant replenishing of the make-up oil at OCI every 3k miles.

I'm going to take a guess and estimate the total system capacity is perhaps 14 quarts? So every 12k miles you're replacing a gallon out of 3.5 gallons. At 20k miles, you've replaced about 1/2 the total system capacity (give or take a bit).

You're getting a big shot of new oil to bolster the already clean oil. Hence, the TBN actually going up from your last UOA. Iron pace slowed nicely (from 10ppm at 10k to 13ppm at 20k). All else looks great. Certainly can't argue with the UOA results.

With such a frequent BP filter OCI and top off program, have you considered using a quality dino HDEO? I would think that there could be even more savings, with similar UOA results.
 
The system capacity is about 13 qts. At the interval at which I replace oil its going to take about 100K miles for the oil to "mature", at which point the average age of the oil will be around 30K miles and it will no longer increase. 30K seems like a lot of miles to put on dino oil, which is why I'm sticking with synthetic.
 
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Well, by topping off so very often, you're replenishing the add-pack often, as the UOA shows (the TBN actually increasing).

And if you keep the oil "clean" with bypass filtration (as you are clearly doing) then "dino" oil has every bit of a chance to live a long life as does "synthetic".

After all, lubricants actually do not "wear out"; they get contaminated with wear metals and byproducts of combustion, and the additive packages get depleted. By using the MG filter, you're addressing these issues. You're cleaning the oil to a very good level, and bolstering the add-pack with every top off (as a high percentage of the total system).

In regard to combustion byproducts, neither oil has an advantage, as they don't affect the production of the acids, soot, etc; these are functions of the engine design and operating efficiency. The add-pack of both dino and syn can be tailored to deal with these byproducts, but neither fluid has an advantage other than what is put into the oil as an add-pack. In this regard, oils are "reactive"; they only "treat" what occurs by the natural operation of the engine.

In regard to wear metals, some could reasonably aruge that synthetic has a bit of an advantage, and I'd agree, but it's a very small advantage at best. Most wear occurs at start up; we all know that. So it is your start/stop cycles that effect wear much more than the actual lubricity of the oil. Once up to operating speed (idle or above) it's the hydro-dynamic oil wedge that seperates the crank, etc from the bearings. Pistons and rings do see some scuffing with the cylinder walls, but overall the lubricity of the oil keeps this in check. The synthetic advantage is there, but it's very small in reality.

That leaves the topic of add-pack depletion. Most of the "TBN" is consumbed by oxidation or combating acids. Today's lower sulphur oil/fuel mean there is much less acid production (hence the lower TBN in today's CJ-4 oils). If you can keep the oil "clean" with bypass filtration (keeping soot and insolubles low), and the acid production is low, then TBN will stay higher, for longer periods.

Synthetic fluids have a great advantage over dinos when using traditional full flow filter systems. But when bypass systems are added into the equation, the fluid advantage is greatly diminished. It's still there, but it's much less that the former set-up. Where is the real "synthetic" advantage if you keep the dino oil clean and TBN bolstered with constant top-offs?

I would think you'd be pleasantly suprised at how well a quality dino fluid would do with your particular set up. Unfortunately, most people that run bypass filtration in light-duty trucks also use synthetic fluids. There are not a whole lot of UOAs to show that dinos with bypass are a viable option; very few people actually use such as set up. It's more common in OTR applications, but we don't see a whole lot of UOAs in that regard.

Granted, RTS is a great performing fluid, but it still costs probably 2x what dino Rotella costs. It's a question of fiscal choice. You surely might get 10% more life from a "synthetic" oil when using bypass filtration, but if it costs 100% more money over the dino fluid, where's the real benefit?
 
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I would say you have definitely found a good setup, and the results looks great.
Also consider the Donaldson ELF 7349 or the Amsoil EAO 80 for your FF...they are 15 microns at 98.7%, as opposed to the FS which is 25, with the same great benefit of synthetic media.
Looks great.
 
dnewton3: You make a very compelling argument. If I were to do this over I would be tempted to try it with a conventional oil.

I will probably stick with the Rotella Synthetic though simply because its what I use in all my other vehicles (which I am not using a bypass filters in) and the increased cost of a gallon of syn vs. dino every 10K miles is pretty negligible.
 
Originally Posted By: dnewton3
I would think you'd be pleasantly suprised at how well a quality dino fluid would do with your particular set up. Unfortunately, most people that run bypass filtration in light-duty trucks also use synthetic fluids. There are not a whole lot of UOAs to show that dinos with bypass are a viable option; very few people actually use such as set up. It's more common in OTR applications, but we don't see a whole lot of UOAs in that regard.

I know of a couple that run over the road in a straight truck (expedite) that went over 100K on their initial OCI with dino .... after installing a bypass setup on their rig. Motor was a CAT C15 .... large sump, and of course the amount of make up oil they were adding was measured in gallons, not quarts.
 
thejessman - I'm not trying to diminish your decisions, as only you know what is right for your situation.

I can see the logic in having a reduced lubricant inventory by keeping as few oils as possible (although, this goes against every fiber of a BITOGers being -
LOL.gif
). If you're using RTS in other vehicles that don't have bypass, it probably makes sense to use RTS across the board for convenience. It (RTS) is a fantastic product to be sure.

I just like for people to uderstand the abilities of dino fluids today, especially when pared with premium filtration. To coin a phrase, they are not your grandpa's oil ...
 
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dnewton and I are always in agreeance when it comes to dino oils and their ability to protect admirably. I like syn oil also, but most people will NEVER reap the benefits of syn oil.

With your setup, I would w/o a doubt be running a top shelf dino HDEO and wouldn't change your full flow out for another 10K minimum. The stratapore is a VERY good full flow oil filter.
 
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