Amsoil 5W30 or 15W40?

[CKniffin]

Is there any advantage of the 5w30 synthetic over the synthetic 15w40? I live in Tenn so my truck (2005) doesn't see alot of cold weather, so I guess I'll go with the 15w40. Any opinions Thanks

 

[roperteacher]

I live in sunny Southern Calif and put the 15/40 in mine. I love AMSOIL but didn't see any real performance gains etc so on the next change went back to the Rotella 15/40 Dino.

 

[jelag]

As touchy as the dealer is... I would not use any oil other than one suggested by Cummins..... if they suggest 15-40 that would be my choice... ... these engines are expected to work hard, and last for 500K miles, I wouldn't risk that... .

Just my thoughts.....

 

[amsoilman]

Is there any advantage of the 5w30 synthetic over the synthetic 15w40? I live in Tenn so my truck (2005) doesn't see alot of cold weather, so I guess I'll go with the 15w40. Any opinions Thanks

Either one would be OK, as they both meet the Cummins Specs. I've used both over the years. The 5W-30 may get you a tad more MPG, then the

15W-40, but it is more costly. Both will protect the same!



Wayne

amsoilman

 

[AKaiser]

Amsoil 5W30 HDD meets Cummins specifications for lighter-than-standard oil for this particular engine. Having said that, I would opt for the DEO 5W40, as it meets all standards for the CI-4+ and the CJ-4, and if you refer to the Valvoline paper, you'll see what I'm talking about. It is within this post linked at https://www.turbodieselregister.com...3-dodge-synthetic-engine-oil.html#post1761675



For the Cummins standards, see https://www.turbodieselregister.com...-synthetic-oil-suggestions-2.html#post1739300