Cummins 6.7L general questions

[56Cummins]

What does a 10-30 become?

When i tested the 10w30 in my 2017, the typical properties were listed as 12cst for virgin oil. After my drive cycles in a full index, even with over 2% fuel on one of them, the oil was 11.47cst. I would say that is pretty stout.

I poked around in the uoas, yours did better than most.

Most were fords, and they ended roughly 10-10.999cst. Still solidly in the 30 range.

 

[Fishstyx]

Got my hands on a owners manual for a 2023 2500 and it says the engine was designed for the use of a full synthetic motor oil which to me says 5-40

 

[#18FAN]

Got my hands on a owners manual for a 2023 2500 and it says the engine was designed for the use of a full synthetic motor oil which to me says 5-40

Or a quality 15w40

 

[MSCH]

Got my hands on a owners manual for a 2023 2500 and it says the engine was designed for the use of a full synthetic motor oil which to me says 5-40

Fishstyx, you need to re read anything Mopar puts out.. their manuals are poor.. and somewhat misleading...

this is what the OM says on page 398 of the 2024 Owners Manuals..

Quote:
In ambient temperatures above 0°F (-18°C), we recommend using 10W-30 engine oil such as Mopar®, Shell Rotella and
Shell Rimula that meets the manufacturer Material Standard MS-10902 and the API CK-4 engine oil category is required.
Products meeting Cummins® CES 20081 may also be used. The identification of these engine oils is typically located on
the back of the oil container.
In ambient temperatures below 0°F (-18°C), we recommend using 5W-40 synthetic engine oil such as Mopar®, Shell
Rotella and Shell Rimula that meets the manufacturer Material Standard MS-10902 and the API CK-4 engine oil category
is required.

 

[OLEJOE]

or ETM)
DISCUSSION:
For all trucks, regardless of model year, located in areas where the ambient temperatures routinely fall below 0°F (-18°C) during the winter, it is required to use 5W-40 synthetic engine oil. Although this grade of oil is required in colder climate areas, it is also safe to use during the summer months, and in warmer climates as well.
Per the TSB and my dealer.

 

[Fishstyx]

Fishstyx, you need to re read anything Mopar puts out.. their manuals are poor.. and somewhat misleading...

this is what the OM says on page 398 of the 2024 Owners Manuals..

Quote:
In ambient temperatures above 0°F (-18°C), we recommend using 10W-30 engine oil such as Mopar®, Shell Rotella and
Shell Rimula that meets the manufacturer Material Standard MS-10902 and the API CK-4 engine oil category is required.
Products meeting Cummins® CES 20081 may also be used. The identification of these engine oils is typically located on
the back of the oil container.
In ambient temperatures below 0°F (-18°C), we recommend using 5W-40 synthetic engine oil such as Mopar®, Shell
Rotella and Shell Rimula that meets the manufacturer Material Standard MS-10902 and the API CK-4 engine oil category
is required.

Well here’s the most current one

 

[Redhawk454]

Well here’s the most current one View attachment 184168

Shell rotella t4 10w-30 diesel oil is CES 20081 approved btw

 

[Redhawk454]

Got my hands on a owners manual for a 2023 2500 and it says the engine was designed for the use of a full synthetic motor oil which to me says 5-40

I think that’s the Hemi but obviously full synthetic isn’t going to hurt a 6.7 Cummins.

 

[Fishstyx]

I think that’s the Hemi but obviously full synthetic isn’t going to hurt a 6.7 Cummins.

Well it’s in section four diesel so If I decide to buy I am just going with 5-40 and not worry.

 

[MSCH]

Well here’s the most current one View attachment 184168

I know, but somewhere else in that page it tells you to go to page 402... that donut on that page is misleading

 

[Redhawk454]

Well it’s in section four diesel so If I decide to buy I am just going with 5-40 and not worry.

Good choice going with the 5w-40.

 

[Fordiesel69]

Let me preface this I am asking for advice backed up with empirical evidence. I know that a lot of people have great opinions about stuff. I am trying to understand somethings. Okay I am probably going to bite the bullet and buy a new Ram 2500 with the 6.7L Cummins. I know that it’s recommended to run 10W30 but in the winter recommend 5W40. I really don’t want to change oil in October just to change it again in April. Summer temperatures are triple digits yet winter temperatures get below 0 for a while. Is it safe to run 5W40 year around even in 100 degree weather. I know there’s someone who probably has and that’s fine but they aren’t making my truck payment. So please respond with evidence based responses. Thanks and I am not going into a debate on Rotella v Valvoline. I know Cummins recommends it while Ram recommends Rottela only because Rottela has a contract with dealerships service departments. So I think either one is fine.

Becuase I do all the maint, I ran 5w40 all year on my dads 2003 Ford Excursion 6.0L powerstroke to eliminiate the issues with the cold starting. This was before ford released the inductive heating flash on the PCM / FICM firmware. It was the only solution that worked if you wanted to not plug it in. Running it in the summer did not cause premature wear of any kind. After we sold it at 100k, the next owner did the same and it entered into the mid 200k before we lost contact with him. The cummins 6.7L is a better engine in every regard however.

Most of diesel engine wear occurs from wet stacking (prolonged idle) and cold starts. The 5w-40 can only help you with that.

 

[Redhawk454]

Becuase I do all the maint, I ran 5w40 all year on my dads 2003 Ford Excursion 6.0L powerstroke to eliminiate the issues with the cold starting. This was before ford released the inductive heating flash on the PCM / FICM firmware. It was the only solution that worked if you wanted to not plug it in. Running it in the summer did not cause premature wear of any kind. After we sold it at 100k, the next owner did the same and it entered into the mid 200k before we lost contact with him. The cummins 6.7L is a better engine in every regard however.

Most of diesel engine wear occurs from wet stacking (prolonged idle) and cold starts. The 5w-40 can only help you with that.

Just curious, what is your definition of prolonged idling?

 

[MSCH]

Just curious, what is your definition of prolonged idling?

I have my own.. if it is going to idle for more than 5 minutes I put the fast idle on...

good thing on Rams is you can activate the fast idle by
having it in Park and activating the cruise control and hitting SET.
you can also bump up the fast idle speed by hitting the set button.