FA-4, yay or nay?

[Bigwalnuthoney]

Thanks, this is my thinking.. why even tell people to run 10w30 then if the 5w40 covers both temperature bases even further & (possibly) better? Fuel economy? I really have never understood this when it comes to an either or scenario.

I'd like to know that answer too. There has to be some reason they say 10w30, otherwise they would just say 5w40 across the board.

 

[Southernspeed]

I'd like to know that answer too. There has to be some reason they say 10w30, otherwise they would just say 5w40 across the board.

Puzzling eh? Why don't we all use Mobil 1 0w50 and be done with it! I like the idea of 10 weight base but I also like the idea of a 40 upper viscosity. Yet they state that post 2019 mustn't use 15w40 as it can gum up and leave heavy deposits causing lifter failure.

 

[MEGA HO]

Puzzling eh? Why don't we all use Mobil 1 0w50 and be done with it! I like the idea of 10 weight base but I also like the idea of a 40 upper viscosity. Yet they state that post 2019 mustn't use 15w40 as it can gum up and leave heavy deposits causing lifter failure.

Post 19? How is 20-22 different from 19? Same engine AFAIK. Pre 19 are different

 

[Southernspeed]

Post 19? How is 20-22 different from 19? Same engine AFAIK. Pre 19 are different

19 inclusive, but you knew that.

 

[H3LZSN1P3R]

Thanks, this is my thinking.. why even tell people to run 10w30 then if the 5w40 covers both temperature bases even further & (possibly) better? Fuel economy? I really have never understood this when it comes to an either or scenario.

Higher temp areas the 10w30 would be the better choice only because of the hydraulic lifters these engines now run

 

[AEV_CUMMINS]

Higher temp areas the 10w30 would be the better choice only because of the hydraulic lifters these engines now run

Understood but in what area do they help the lifter when the 5w40 would be thinner and easier moving around the lifters when mild or cold and thicker when hot? I am honestly curious how it would be better in any scenario?

 

[Dave88LX]

All this oil stuff is confusing.
I live in PA, where it's normally above 0° F even in the winter, but there is the occasional night where it might dip below, or a trip to New England where it could get a little colder.
Seems like 10W30 would apply for 97% of the time but 5W40 for the other 3%.
What are people in these climates doing?

 

[Dave88LX]

Tell you one thing, nobody seems to stock any of this 10W30 locally.

 

[dslbrnr]

This is what I use. I order from Speedway Motors online

Mobil Delvac™ Extreme 10W-30 | Mobil Delvac™ Engine Oils

Learn how Mobil Delvac™ Extreme 10W-30 synthetic diesel oil can help prolong engine life and reduce oil changes.

www.mobil.com

 

[H3LZSN1P3R]

All this oil stuff is confusing.
I live in PA, where it's normally above 0° F even in the winter, but there is the occasional night where it might dip below, or a trip to New England where it could get a little colder.
Seems like 10W30 would apply for 97% of the time but 5W40 for the other 3%.
What are people in these climates doing?

That 3% wont matter

 

[JW99]

So on my 22 the oil information says this. Doesn't say anything about using the 5 all time. Most likely 10. I live in the desert. 110 summer and winter in the teens, usually 20s-30s.

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.


With this information, what is everyone really using?
JW

 

[21Tradesman3500]

I'm using Rotella T4 10W-30 (non-synthetic) at the moment, mainly because I couldn't find any T6 5W-40 or even T5 10W-30 at the time of the last oil change. I will likely go back to either T6 5w-40 (full synthetic) or T5 10W-30 (synthetic blend) at the next oil change.

 

[steve49]

I live in northeastern AZ where the winter temps get down to freezing, and since T6 5W-40 can also be used in the warmer weather as well, that's what I use! It's a good full synthetic oil and very popular heavy duty diesel oil, and good coverage when you happen to travel to a colder area from where you live.

 

[H3LZSN1P3R]

So on my 22 the oil information says this. Doesn't say anything about using the 5 all time. Most likely 10. I live in the desert. 110 summer and winter in the teens, usually 20s-30s.

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.


With this information, what is everyone really using?
JW

I run 5w40 year round, for you if you are not hauling heavy constantly id say 10w30 is good

 

[John Jensen]

I'm in SoCal, rarely hit 32 or 90. T6, 5w-40 100%

 

[AEV_CUMMINS]

If you think about which will handle better when at operating temp in your warm climate, the 30 number or 40 number.. I would always say 40. I know that when I am driving hard that 5w40 has coverage on both ends of the spectrum. For the folks that say because of all the viscosity modifiers used to make a 5w40, it is not as good since it will break down faster yada yada yada, I change the oil far sooner than the max or even recommended interval and do UOA which always reminds me why I do not mind a wide spread like the 5w40 is. My Nissan GTR runs 0w40 and I can say whether it was on a track day, or going out to do some winter sliding.. the engine felt smooth as butter from warm up to shut down. Same thing with this big Cummins girl. Other than the fuel economy gain maybe, I do not see a point to using 10w30 over 5w40.. especially considering 5w40 is almost exclusively high quality synthetics.

 

[dslbrnr]

I just follow the recommendations in the owners manual for the climate in the area of operation. My Cummins seems happy with CK-4 10-30. It doesn’t say anything about towing heavy needing 5-40 but whatever let’s you sleep at night is what you should use