What oil to use in 5.9L Cummins?

[jc49]

Originally Posted By: 1sttruck
Isn't Amsoil 3000 a 5w30 ? Kind of thin.


i thought the same thing, amsoil recomends it as their "premere" and also most expensive diesel oil so i used it. didn't work out so good.

 

[jc49]

Originally Posted By: cowhorse01
I am sure Dave will chime in here, but I would say along his thought processes and from I have learned myself using Amsoil for the last 5 years. I love Amsoil and like synthetics, HOWEVER, if you are not going to do longer OCI's, synthetics don't provide the amount of protection commensurate with the money you pay. You would do more than fine using something such as Valvoline Premium Blue Dino (Cummins factory fill)and running for 7.5-10k miles and spending less money. I ran my last diesel (Cummins) for 380,000 miles before trading it in and it was still running frickin' fantastic. I ran VPB 15w-40 at 7k mile OCI's and had NO problems engine wise. This is just something to think about. Synthetics provide the ability (sometimes) to run longer change intervals, not better protection over Dino HDEO, which are all very capable oils, IMO. And just on a personal note, I no longer use Amsoil. I switched to using Dino last month by realizing the the UOA's, inconvenience of having to order online, and not always getting comfortable results with UOA's, that I could just run a good dino, change every 10k, and be more than happy and well protected. Good luck on your search.


what are you back to VPB 15w-40?

 

[jc49]

Originally Posted By: trik396
Originally Posted By: jc49
I'm running the Banks Ram air filter, similar to the K&N style filter..

Here are the oil report findings from Blackstone:

JOHN: You switched to a different brand of oil, which shows up in the higher calcium additive. This Amsoil
was in use for 5,500 miles and engine wear increased above universal averages for the Cummins 6 BT.
Some diesels don't do well on synthetics, and yours may be one of them. But another reason for the wear
increase could be anti-freeze, if that's what potassium is. But we think it's more likely potassium is from the
EGR cooler and should improve next time. Change this oil, try going back to Rotella, monitor the coolant
level, and check back in 5K miles.

Diesel
Amsoil Series 3000 5W/30
0 qts
04/11/08
25,288 miles

First off, I don't really understand why you're running 5w/30 oil. Second, Blackstone's comments about potassium coming from your "egr cooler" makes me worry about Blackstone since your 06' Cummins doesn't have one...? We do have an oil cooler... if that's what they meant.


I agree with you on blackstone, i have questioned their integrity when they make statement like this... I will be using another testing company next time for second opinion..

thanks guys for all your input!

 

[bbslider001]

Originally Posted By: jc49
Originally Posted By: cowhorse01
I am sure Dave will chime in here, but I would say along his thought processes and from I have learned myself using Amsoil for the last 5 years. I love Amsoil and like synthetics, HOWEVER, if you are not going to do longer OCI's, synthetics don't provide the amount of protection commensurate with the money you pay. You would do more than fine using something such as Valvoline Premium Blue Dino (Cummins factory fill)and running for 7.5-10k miles and spending less money. I ran my last diesel (Cummins) for 380,000 miles before trading it in and it was still running frickin' fantastic. I ran VPB 15w-40 at 7k mile OCI's and had NO problems engine wise. This is just something to think about. Synthetics provide the ability (sometimes) to run longer change intervals, not better protection over Dino HDEO, which are all very capable oils, IMO. And just on a personal note, I no longer use Amsoil. I switched to using Dino last month by realizing the the UOA's, inconvenience of having to order online, and not always getting comfortable results with UOA's, that I could just run a good dino, change every 10k, and be more than happy and well protected. Good luck on your search.


what are you back to VPB 15w-40?


Yeah jc, as a matter of fact, I did go back to using VPB 15w-40 in my Duramax. I'll just do 10k mile changes and not worry about UOA's and all that other stuff. Horses take up so much of my time, I needed to simplify....Dmaxes are really easy on oil, so any dino would do, but I have always been a big fan of Valvoline oils, so I went with what has done me well in the past.

 

[440Magnum]

Originally Posted By: jc49
I'm running the Banks Ram air filter, similar to the K&N style filter..


Hmmmm..... I'm very wary of single-layer oiled cotton air filters in motor vehicles. They seem to let a LOT of dirt through.

When you say its "similar" to a K&N, that's what I think of. Is it in fact a multi-layer filter instead?

The UOA doesn't show high silicon, so it may not be the problem.

From everything I've read about the Cummins, you should be running an Xw40 oil- either 15w40 or 5w40

 

[opposite_locker]

If price is no object, Redline 15w40 diesel.

For extended OCI, Amsoil 5w40 or 15w40 with a bypass filter

For the best "mainstream" synthetic, Mobil 1 5w40 TDT or Delvac 1

For a good value-priced synthetic, Rotella Synth 5w40

For normal OCI's, a good 15w40 dino oil like Delvac, Rotella, or Delo

I personally use Delo in my 12-valve with a 5k OCI.

All of the above is opinion only so should be taken with several grains of salt.