Buster I recenty asked the same question to a specialty MC oil blender, who bar graphs elevated zinc/phos on there web site, but labels the product SL. The answer I got back, FWIW:
"Our oils start out with the API SL additive system (the industry's latest and greatest) that was designed to meet and PASS API SL LICENSING requirements.
Thus, they meet all of the API SL quality standards. Then, we up-treat the ZDDP portion (anti-wear additive) significantly.
This would disqualify us for the API SL LICENSE (there is a ZDDP maximum limit)....but not lower the quality standard, so, we still meet the SL quality levels!
But, we are not API SL LICENSED. (We do not want to be)
API SG/SH are done and gone forever which is why the API will not even allow us to place SG,SH on any labels at all, licensed or not. We can put SL on there in the context we are using.
Yes, partly semantics. But not designed or used to fool or miss-lead you.
Here is the best part. Our oils are then sent for performance tests that are tougher than the API SL tests, the new JASO T-903 series of tests that add tougher shear stability and volatility tests and add the critical clutch stop time tests (like a slip test) to ensure the oil will not make your motorcycle clutch slip (API SL does not have these tests for obvious reasons) and also will hold up in your gearbox. And, the JASO MA license has no maximum ZDDP anti-wear additive level!
Bottom line: We make motorcycle specific formulations that are JASO T-903 tested and JASO MA licensed.....we were the first non-OEM in the USA to do this. And we guarantee that the oils marked with the JASO symbol pass the T-903 tests. But remember, these oils are not for use in your car."
