Difference Between SL, SM, SN?
- Thread starter Gebo
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Originally Posted By: Gebo
I understand but where can I find what they changed from going from a SL to a to a SM to a SN? Like the Phosphorus went from "X" to "Y".
This , https://www.infineum.com/media/80723/api-engine-oil-classifications.pdf
I understand but where can I find what they changed from going from a SL to a to a SM to a SN? Like the Phosphorus went from "X" to "Y".
This , https://www.infineum.com/media/80723/api-engine-oil-classifications.pdf
Go to this web page and download the spec handbook (it's free). You'll find the detailed answers you're looking for inside...
https://www.aftonchemical.com/News/Pages/UpdateonlineSpecificationHandbook.aspx
In the US, where Group II base oils have been available for many years, it's probably fair to say there was very little material difference between SL, SM & SN oils.
Outside of the US, where Group I base oils were the norm for much longer, there was a very big difference between SL and SM/SN oil. The difference derived from the move from the 80 hour Sequence IIIF engine test to the 100 hour Sequence IIIG. You can pass the IIIF easily with neat Group I but not the IIIG for which you need Group II or a Group I/III blend.
Although it never bothered me at the time, in retrospect the introduction of the severe IIIG test looks a bit suspect and somewhat self-serving. At a single stroke, it effectively 'killed off' Group I use in engine oil in the US which was very handy if you were a big US oil company who had just invested big in Group II base oil production. In nobbling the competition, you hand yourself a clear run at recouping your investment costs. The spillover outside the US has resulted in many still serviceable European and Asian Group I base oil plants shutting down.
https://www.aftonchemical.com/News/Pages/UpdateonlineSpecificationHandbook.aspx
In the US, where Group II base oils have been available for many years, it's probably fair to say there was very little material difference between SL, SM & SN oils.
Outside of the US, where Group I base oils were the norm for much longer, there was a very big difference between SL and SM/SN oil. The difference derived from the move from the 80 hour Sequence IIIF engine test to the 100 hour Sequence IIIG. You can pass the IIIF easily with neat Group I but not the IIIG for which you need Group II or a Group I/III blend.
Although it never bothered me at the time, in retrospect the introduction of the severe IIIG test looks a bit suspect and somewhat self-serving. At a single stroke, it effectively 'killed off' Group I use in engine oil in the US which was very handy if you were a big US oil company who had just invested big in Group II base oil production. In nobbling the competition, you hand yourself a clear run at recouping your investment costs. The spillover outside the US has resulted in many still serviceable European and Asian Group I base oil plants shutting down.
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Good reference from that "paper". Thank you.
I just compared the VOA of the oils and tried to figure what additives changed.
Not really scientific, but you get a handle of what the company is doing.
I just compared the VOA of the oils and tried to figure what additives changed.
Not really scientific, but you get a handle of what the company is doing.
My engine has been run on Group I conventional oils for most of its life and now has over 150k miles without any of the internals being touched which is quite a bit for a 70s engine, and still has good compression and oil pressure
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