Mystik JT-8 15w40, 2015 RAM EcoDiesel, 4,995 mi

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Here's my latest UOA. Ran this over the warmer months with some towing of our Jayco Jayflight 264BH this summer and fall. Wear metals appear to be better. It was interesting* to see the differences between the different viscosity grades. Possibly from the higher viscosity, moly, or zinc?

The two previous samples are labelled wrong. They should read as:

March 18 = Rotella T6 0w40
Juky 14 = Mobil 1 Turbo Diesel Truck 5w40

*I do these UOA's for fun and realise that this isn't scientific data

20181212_103254.jpg
 
Looks like the MUCH less expensive Mystik protects just as well as the more expensive full synthetics. If Blain's Farm & Fleet stores were closer to me, I would run their Mystik JT-8 10W30 in everything, they've had it as low as $25/5gallon pail AR, or $1.25/qt.
 
The Ecodiesel (FCA) manual specifies 5w40 per the updated 2016 Diesel Supplement...

"We recommend you use 5W-40 synthetic engine oil such as MOPAR or Shell Rotella
that meets FCA Material Standard MS-10902 and the API CJ-4 or ACEA E9/E7 or
ACEA A3/B4 engine oil category is required."
 
Perfect example of why paying for more does not always get you more.
The UOAs show the engine is in fine condition. Low wear metals and no contamination.
Honestly, it's probable that this engine in no way "needs" a 5w-40 syn, especially for 5k mile OCIs.
While under warranty, best just to do what you're told though.
 
^^Agree^^
Why on earth do people feel paying more for something with the EXACT same rating (in this case API) gets you better protection?
Its a fool who thinks the marketing of major oil companies that gets you to pay crazy prices for oil of the same rating = more profit for them.

Mystik is a fine oil, really a "best kept secret" in the agriculture industry.
What is even more crazy, its produced by Citgo, a major refiner, who also produces private labeled oils.

For those interested, I have run Mystik JT8 15/50 in my 2014 Harley Road king since maybe after the first 2 oil changes which is almost 4 years now and I just ran yet another UOA on the oil two weeks ago and posted in BITOG.

Here is the link to the UOA or go down to the Powersports UOA section.

All SIX UOAs on the page are the Mystik JT8 15/50 and always turns in great wear numbers and why shouldnt it? Its a great oil at a realistic price with the same exact rating of oils that cost 500% more.
Dont get me wrong, for me, its not about buying less expensive oil, its about using the proper weight oil with the proper API recommended by the manufacturer.
 
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Thanks for posting.

Is there any concern for poisoning the SCR & DPF with the 15w40?

I have the same motor in a Jeep Grand Cherokee;
I'm curious as to if I missed a discussion of this...
 
Originally Posted by 390pi
Thanks for posting. Is there any concern for poisoning the SCR & DPF with the 15w40? I have the same motor in a Jeep Grand Cherokee;
I'm curious as to if I missed a discussion of this...


The Diesel Supplement I quoted was from my 2016 Jeep GC. Any risk would be the same for the 5w40 or 15w40 since the SA is limited to 1.0% max. I just think the 15w40 is too heavy for a VM motor that specs 5w30 in Europe and was changed to 5w40 due to our North American driving habits, IE: long distance travel.
 
Originally Posted by 390pi

Is there any concern for poisoning the SCR & DPF with the 15w40?


No concern at all. But the 15w40 has nothing to do with whether or not it's safe for exhaust aftertreatment systems. You need to look at the oils spec. In this case it's CK-4 (midSAPS) which is safe for aftertreatment systems. It would be safe in your Jeep GC EcoDiesel. If you can find an oil that is CK-4 and CES-20081 then you'll be even better.

20180629_102937.png


Screenshot_20181214-162651.jpg
 
Originally Posted by BoiseRob
I just think the 15w40 is too heavy for a VM motor that specs 5w30 in Europe and was changed to 5w40...


C'mon Rob! A 5w40 and 15w40 are the same weight (heavy) when warm. Unless your climate dictates the use of a 5w for cold starts the 15w is fine.

Where in my posted UOA are you seeing that the 15w40 harmed the engine?
 
Originally Posted by BoiseRob
The Ecodiesel (FCA) manual specifies 5w40 per the updated 2016 Diesel Supplement...

"We RECOMMEND you use 5W-40 synthetic engine oil such as MOPAR or Shell Rotella
that meets FCA Material Standard MS-10902 and the API CJ-4 or ACEA E9/E7 or
ACEA A3/B4 engine oil category is required."

Fixed it for you. They only recommend, not require.
FCA interest is getting you to end of warranty, nothing else. That's why the switch, engines were self destructing. The UOA doesn't lie, (at least not too much).
Off topic, in my Powerstroke it's "RECOMMENDED" a 5w40 is used for severe service. I've settled on 15w40 as optimum for wear in my truck, for my use.
OP, I say you did good, and agree Mystik is a sleeper. Keep on keepin' on.
 
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Originally Posted by BoiseRob
Originally Posted by 390pi
Thanks for posting. Is there any concern for poisoning the SCR & DPF with the 15w40? I have the same motor in a Jeep Grand Cherokee;
I'm curious as to if I missed a discussion of this...


The Diesel Supplement I quoted was from my 2016 Jeep GC. Any risk would be the same for the 5w40 or 15w40 since the SA is limited to 1.0% max. I just think the 15w40 is too heavy for a VM motor that specs 5w30 in Europe and was changed to 5w40 due to our North American driving habits, IE: long distance travel.


I've run 15W40 in summer in my EcoD, the 15 is a cold flow number, 40 is a warm flow number generally 12-14 Cst, above 32F ambient temperature it doesn't matter if you have 5W40, 10W40 or 15W40 or even SAE40, when the engine is warmed up their viscosity is basically the same. It just makes matters easier for explanation if you state 5W40, it will cover basically all temperatures from -20F to 120F ambient, thats why FCA does this.
 
Originally Posted by SavagePatch
C'mon Rob! A 5w40 and 15w40 are the same weight (heavy) when warm. Unless your climate dictates the use of a 5w for cold starts the 15w is fine.

Originally Posted by Fraser434
I've run 15W40 in summer in my EcoD, the 15 is a cold flow number, 40 is a warm flow number generally 12-14 Cst, above 32F ambient temperature it doesn't matter if you have 5W40, 10W40 or 15W40 or even SAE40, when the engine is warmed up their viscosity is basically the same.


15w-40's are typically heavier for the grade than 5w-40's and 0w-40's. This is not only evidenced by this UOA, where it was heavier, but also by the PDS's for various products. Yes, they all fall within the range for the xw-40 designation, but typically the 15w-40's will have a higher 100C visc and higher HTHS.

The products being discussed:
Mystik JT-8 15w-40:
100C visc: 15.5cSt
HTHS: 4.0cP

Rotella T6 0w-40:
100C visc: 13.2cSt
HTHS: N/A

Mobil 1 TDT 5w-40:
100C visc: 14.5cSt
HTHS: 3.8cP

The Rotella is closer to the upper limit for xW-30 (12.5cSt) than it is to the Mystik product, which in turn is closer to the upper range of the xW-40 designation (16.3cSt).
 
Recall seeing somewhere that T6 5w40/0w40 HTHS is right about 3.5 (the lower limit). That's presumably why they try to conceal their HTHS value from the public.
 
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A working diesel engine should have a 40WT oil used in it at all times, the only reason the latest trends to use 20 and 30 WT's is for economy and other CAFE BS. A diesel is a compression ignition engine that burns a dirty fuel and creates soot, it has higher temps and much more forces exerted on the internal components. It doesn't matter how old or new the engine is. Sure the manufacture is going to suggest or recommend whatever they have to according to the CAFE standards and to just squeak through warranty. If you own a diesel in a cold climate use a 5W40, if in a warm climate a 15W40. It really is that simple.
 
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Originally Posted by racin4ds
A working diesel engine should have a 40WT oil used in it at all times, the only reason the latest trends to use 20 and 30 WT's is for economy and other CAFE BS. A diesel is a compression ignition engine that burns a dirty fuel and creates soot, it has higher temps and much more forces exerted on the internal components. It doesn't matter how old or new the engine is. Sure the manufacture is going to suggest or recommend whatever they have to according to the CAFE standards and to just squeak through warranty. If you own a diesel in a cold climate use a 5W40, if in a warm climate a 15W40. It really is that simple.


If this is a true statement, why are ALL OTR semi's delivered with 10w30 in the sump. They are THE "true" working diesels...

My "07 LBZ duramax has had 10w30 in the sump since 2008. I tow a 10k pound TT throughout the Idaho mountains, as well as hauling across southern Idaho, which is desert, with temps up to 110 degrees in summer...
 
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