Here I am

Oil roll call- older engines only please.

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

UDC Pro Survey

Changing oil too soon is bad??

By "light" are you referring to 10w30?
I guess I’m refering to the FA4 oil. That comes in 5/40 or something like that?
That’s part of the reason I started this- there’s a lot of confusion.
I’m trying to recruit co worker who recently got a ‘18 tradesman, so I gave him the buyers guide and I read in there that the factory oil is a synthetic 5/40- adding to the confusion.
Life was so much more simple when everyone took 15/40 unless you were in the extremes.
 
The difference is not so much viscosity as HTHS (HIgh Temperature High Shear). The FA4 oils have a low HTHS of something like 2.8-3.2 cp, the CK4 oils have a MINIMUM HTHS requirement of 3.5. This is essentially an oils ability to resist flow under loaded journal bearings. FA4 is a "lighter" oil as it is geared towards the new GHG requirements. There's more to it than that but for simplicity sake anything that carries the CK4 spec- or more specifically for the ISB any oil that carries CES20086 - is compatible for ANY ISB.

Viscosity should be selected based on ambient temps. 5*F and above -15w40. Below 5*F - 5w40. Many here have reported 5w40 being factory fill and it somewhat makes sense as they do not know wether the truck is headed for Florida or the north slope.
15w40, 5w40, and 10w30 are all available under the CK4 spec. where it gets tricky is if one were to run 10w30 you'd have to watch for the correct label.

Many on here are concerned about the new oils and lack of zddp, it is my opinion it just isn't an issue anymore. If you dig into some of the manufacturers tests that are required for the new certification they are more stringent than previous oil specs.

Like this one for instance. This as it relates directly to a comparison between phosphorus and new ashless AW compounds

t4Y1gbZ.png
 
Last edited:
@NIsaacs I guess I am not making my point.

Flat tappet cams are not as good as roller cams as far as oil goes. I do not know how Cummins overcomes not using roller cams. On the surface (fair or not) one could dismiss the failed Cummins cams at the engine rebuilders for this reason alone. However I am seeing and personally wiping out roller cams. So do we take the higher oil temps of Phoenix AZ thinning out oil, reduced oil cooling from hotter air over the oil pan and oil cooler, AC load and extra heat into the cooling stack... All take oil to the edge of the max temp it can protect at. How many monitor oil temp of the engine?

The 1/4 million mile 3.9 V6 towed a trailer scrap metal for the Boy Scouts using Mobil1 2-3x a week. Maybe oil changes went too long in our heat. Even stock power levels eventually take it's toll.

The 6.2 I wiped the cam in is anything but stock. How many tuners are being run on Cummins trucks getting closer to the edge of what modern oil can take? The hot rod 6.2 burned and surface cracked the piston crowns. (Glow plug erosion indicates too much advance contributing or the sole cause of this damage.) Turbo 6.5's have a coating on the piston crowns and later production went to oil squirts to cool the pistons. The next 6.2 I am building has coated pistons on the way for it to keep the oil cooler.

IMG_20181119_225026887.jpg
IMG_20181119_225227895.jpg


I have been told to run a better oil in the 6.2 by a couple of people and had to tell the retired fleet manager: "We already ran Shell in it... and now run 15w-50 to keep oil pressure up at hot idle". Same advice from the person coating the pistons: run a better oil and a bigger oil cooler.

Expanding on tuners on Cummins trucks: I already have oil samples off another 6.2 I hot-rodded showing conventional oil failing at 1500 miles and completely ruined at 3000 miles. The difference was adding a BD spool valve to the rig. I had to switch to synthetic oil to keep from ruining the oil.

Oil sludge from gasoline engines is still a problem today on some makes.

Conclusion is there are limits to what engine oil can take. Stock power with the "better" cooling Dodge diesels have enjoyed give it an edge in the battle to ruin engine oil. If you run a tuner or take it to other extremes you are not out of line to want a better oil.
 
Last edited:
I attribute the longevity of the B tappets to a few things;
- A large “mushroom” contact area.
- A modest valvetrain/ spring load, keeping the oil shear factor in check.
- A good cam location to catch oil sling off the crankshaft. The bane of V8 cam oiling.
- Lower operating speed. Less friction= less heat.
 
@NIsaacs I guess I am not making my point.

Flat tappet cams are not as good as roller cams as far as oil goes. I do not know how Cummins overcomes not using roller cams. On the surface (fair or not) one could dismiss the failed Cummins cams at the engine rebuilders for this reason alone. However I am seeing and personally wiping out roller cams. So do we take the higher oil temps of Phoenix AZ thinning out oil, reduced oil cooling from hotter air over the oil pan and oil cooler, AC load and extra heat into the cooling stack... All take oil to the edge of the max temp it can protect at. How many monitor oil temp of the engine?

The 1/4 million mile 3.9 V6 towed a trailer scrap metal for the Boy Scouts using Mobil1 2-3x a week. Maybe oil changes went too long in our heat. Even stock power levels eventually take it's toll.

The 6.2 I wiped the cam in is anything but stock. How many tuners are being run on Cummins trucks getting closer to the edge of what modern oil can take? The hot rod 6.2 burned and surface cracked the piston crowns. (Glow plug erosion indicates too much advance contributing or the sole cause of this damage.) Turbo 6.5's have a coating on the piston crowns and later production went to oil squirts to cool the pistons. The next 6.2 I am building has coated pistons on the way for it to keep the oil cooler.

I have been told to run a better oil in the 6.2 by a couple of people and had to tell the retired fleet manager: "We already ran Shell in it... and now run 15w-50 to keep oil pressure up at hot idle". Same advice from the person coating the pistons: run a better oil and a bigger oil cooler.

Expanding on tuners on Cummins trucks: I already have oil samples off another 6.2 I hot-rodded showing conventional oil failing at 1500 miles and completely ruined at 3000 miles. The difference was adding a BD spool valve to the rig. I had to switch to synthetic oil to keep from ruining the oil.

Oil sludge from gasoline engines is still a problem today on some makes.

Conclusion is there are limits to what engine oil can take. Stock power with the "better" cooling Dodge diesels have enjoyed give it an edge in the battle to ruin engine oil. If you run a tuner or take it to other extremes you are not out of line to want a better oil.


Yes, I am unsure of what your point is. It appears that you are saying to be cautious with our (Cummins) oil selection/use, that some oil selection can be/is bad for your engines health.

However, to illustrate your point, you use a V/6 gasser and a light duty V/8 diesel (hot rod) that failed. Then you say this: (Glow plug erosion indicates too much advance contributing or the sole cause of this damage.)

Personally in my travels, and on three Cummins Forums, I have not seen a trend of oil related failures. I do not know anything about technical specs of oil that has evolved in the past 20 years. If it says 15/40 diesel engine oil, I use it. Maybe I am just uninformed and happy with my Diesel rigs.

I will also add to Wayne's list.....medium duty engine, 3 gallon oil pan with heavy duty/high volume oil pump and cooler, intercooler, pretty good cooling system and a whole lot of just daily driver trucks out there.
 
OK the point of this thread was asking who used what, at least I think so. No offense intended lots of great info shared in above posts and thanks to those whom are more educated and understand all the oil chemistry.
I purchased my 99 in 05/01 with 75k miles. I started out using PB 15/40 then simply for cost reasons switched over to Rotella 15/40 and have changed oil at 3k intervals (maybe overkill, but rather be safe than sorry) and always use Fleetguard filters. 245k miles at present.
 
LOL. Here's what I use in my ancient 28 year old 12v.

https://www.amsoil.com/lit/databulletins/g3467.pdf

The CK4 oil are also more resistant to oxidation, aeration, and biodiesel contenet than either CI4+ or CJ rated oils.

In addition -

"Based on your operating temperature of -40F to 100F range, I highly recommend 0W40 (preferred) or 5W40 for your Cummins engine (CI+4 rated).

Most AMSOIL 10W30 and 15W40 oil contain very few, if any pour point depressants, which is what can cause shear stability to be low. Viscosities like 5Wxx and 0Wxx need more VII’s, thus may not have quite as good HT/HS viscosity. That said. AMSOIL oils use very shear stable VII’s, so this possible factor is not relevant.

The 0W40 DZF does have a high level of ZDDP needed for flat tappet engines. See below:

<P> Phosphorus (ppm)
1206
<Zn> Zinc (ppm)
1314

DZF metals are:

<B> Boron (ppm)
99

Dus8i3Z+QniW%fRYEoWXWA.jpg
DZF.jpg
 
I just finished my barrel of Shell 15-40, now I use whatever is on sale at Mills farm n fleet or theisens. Sometimes DelVac, Travelers, etc.
I am not much help here, but for me, if it meets the spec I am good as I change the oil at 5000-7500 miles regardless.
 
Back
Top