HDEO SM oils

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So I was reading another post, and he mentioned that the oil he bought (A Delo hdeo) was rated SM, along with the diesel ratings. What I am wondering is the fact that it is Sm now instead of SL, Has the ZDDP been lowered??
 
No, not necessarily. The 0.08% max Phosphorus limit in SM only applies to the so-called ILSAC grades (0W20, 0W30, 5W20, 5W30 & 10W30). In 15W40s (the commonest HDDO grade), you can put in as much ZDDP as you like as long as it equates to being greater than 0.06% Phos. I seem to recall as well that the way the rules are written, even if you have say a 10W30 HDDO, as long as you state the diesel spec first (eg CH-4, CI-4, etc), then the following SM claim does not have to comply with the 0.08% max Phos spec.
 
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I just checked PQIA, and found that the SM's still have high zinc and phos. Should have looked first. Thanks for the explanation .
 
It's still a good question to ask once in a while here since the answer is complex and confusing to a lot of people. If you had the question, you can be sure that many others did, too.
 
I think there is a rule change for CK-4/SN, in that the formulation must meet the SN requirement for the grade.
However, CK-4/SM will not be so regulated.
Clear as mud.
 
Are they going to make CK-4/SM?

From what I read the TBN is going to be lower now with the new spec because the additives/metals are going to be reduced, and low sulfur fuels would make up the difference. Is that what is happening, or did I just misread it?
 
I explained the requirement in this post:

Universal oils with CK-4 or FA-4

The footnote changes have been made to the tables for all active API service categories (SL, SM, SN etc). So you will have to respect the phos and other elemental limits on your 5W30 and 10W30 products if you want to claim suitability for gasoline engines. This does not necessarily effect the TBN, however it may have changed the type of chemistry used to get the TBN and how well it is retained.
 
Back to SAE 30 HD I guess
laugh.gif
 
I just got two cases of Delo 15W-30 SD on sale at Amazon with free shipping (not an ILSAC grade). That will be my "Bad" motor break-in oil from now on.

Once the cams/lifters are broken in and the engine is in normal service, I'll run some other oil. Have not figured out which that'll be...

Have to go look at the bottle tomorrow. May be SM, don't know. Will advise ...
 
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