I’m trying to understand your position. Are you a Cummins service center or a Ram service center?
If It’s a Cummins bulletin for their Commercial line of B6.7 engines, they’re a significantly different architecture compared to the FCA 6.7 engine, hence different oil requirements.
Cummins typically does not issue service directives to Ram. Usually that’s done in-house. Granted, Cummins may hand it to Ram, who then hands it down to the dealer network. But it usually never goes from Cummins directly to Ram dealers. Can you clarify?
If there indeed was changes to the oil requirements, a document that specifically states this would help clarify a lot of questions….
My only suspicion if there were changes made to oil recommendations, it would be due to the difference of volatility, foaming, and aeration performance between the two.
Rotella T6 5w40 has a 12.8% NOACK loss
Valvoline P.B. 5w40 has a 11% NOACK loss
Not a huge difference but it’s there. Traditionally Rotella has been known to perform very poorly at aeration and foaming resistance. I have suspicions that this might be part of the issue with the valvetrain issues on our 6.7 engines but it’s difficult to quantify.
Thanks for the inquiry.
So, there are a number of references related to this issue and frankly I have found Cummins response lacking for clarification. We service the Cummins engines in both truck and marine applications. All this started when our field rep, after looking at the 2022 RAM 3500 HD we have here, remarked that the standard CJ4 2018 and older changed to CK4 2019 and newer. So, for truck owners (RAM) FCA bulletin: 09-011-20 GROUP: 09- Engine DATE: July 24, 2020, came into play. So naturally as we are more marine than road, we asked the fatal question what do you want to do with the engines in marine service. The remarks were it's the same engine, just the peripherals are different. So, we went looking for clarification one way or the other. Cummins handed us this, Truck maintenance and operation B6.7 (EPA 2021) and Mopar Technical Service Bulletin MC-10242795-9999 for vehicles.
For marine applications they referred us to the API. We do oil analysis on all our engines for clarification of potential issues.
The API requires a set of lab and engine tests that each commercial oil candidate
must pass in order to meet the requirements for technology advances. API oil categories define the tests and properties required for a specific oil technology. Examples are below.
CI-4 category oils were released in 2002 and updated in 2004, coinciding with exhaust gas recirculation technology, to improve soot control and shear stability.
CJ-4 category oils were released in 2007, coinciding with emissions regulations and ultra-low sulfur diesel fuel, to improve compatibility with aftertreatment, wear control, piston deposits, high temperature stability, and soot handling.
CK-4 oils were released in December 2016 with all the typical viscosity grades of CJ-4 oils. As higher engine temperatures and lower emissions are a continuing trend, improved oils were required. CK-4 has improved oxidation resistance, shear stability, and aeration control. API category CK-4 is backward compatible with API category CJ-4 oil technology.
So, from my standpoint, like you, I would like better clarification one way or the other. But for now, they are "loving" the Valvoline 8600 series, likely resulting from engine lab testing and dealer feedback. I will contine to pursue better documentation and once in hand post it to the forum.
Thanks to all for your indulgence and patience.
On the other issue with the heater, removing it from the air flow and using the BANKS kit (admittedly pricy) resulted in improving the MPG on our 2022 RAM from 14.1 to 19.3. I believe they are pushing the 88% as a broad range improvement in a number of areas related to overall performance as I can't get an 88% improvement in Foot lbs. Torque. I love the hummer you all have. We have noticed that the engine runs cleaner, and the oil is cleaner also, and yes, it's still black. The heater element is improved in the latest version, but most importantly it gives me peace of mind and I'm not worried about the "D" bolt issue.
Sevey