can someone explain differences in API ratings, from SB to SL/SM

[1 FMF]

thanks, but that's not what I'm asking. I've done a search and that kind of info is all I'm able to find. All the article tells me is the service type for the particular rating.
What I want to know is the actual written specification for "S?" ratings. What makes an oil "SL" as opposed to "SH" or "SD"?
Let's say I become an oil blender, just for arguments sake, what do I need to know to make an "SL" or whatever rated oil?
What I am interested in is how the API rating has evolved over the last 20 years, or how they have "improved" oil.

I'd also like to know what the difference between basestock oil groups. What makes a Group I a group I, as opposed to group II, II+, 3,4,5?

 

[1 FMF]

quote:

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from synlube.com: API is also the "rating" that can be found on most motor oils on their back labels with cryptic letters like API SJ or API SH/CF, stuff that 95% of consumers have NO IDEA what it means or represents, and nor do majority of car mechanics.

You can go to API web and spend time to educate yourself about what it all means.

Or you can spend over $100 to purchase that latest copy of API 1509 document (15th Edition) that will give you all the technical and legal specific for each current API "S" or API "C" motor oil rating.

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anyone want to post their copy on bitog?

 

[1 FMF]

something I've been wondering about for a while, but haven't seen any info on it. I refer to the "SB" rating because I just bought some non-detergent 30 weight for my air compressor, and it was "SB" oil. Is/Was there an "SA" oil? What are the specs & technical differences between each rating, over the years?

for example, I've seen some articles referring to the new proposed "SM" oil, which will be called emmision system safe (ESS) I think. They are proposing specific limits on phosphorus, and maybe some other elements (from what I can remember) along with certain viscosity, hths requirements, etc.

[ February 19, 2004, 12:14 PM: Message edited by: 1 FMF ]

 

[TallPaul]

Just search the net for "API oil ratings." Here is one I found that lists all the SL to SA ratings: http://www.performancempg.com/MotorOilRateGas.htm
I have seen similar charts with more details, like what kind of additives. I recall SA and SB have NO additives.