Newbie here. Got a question or two.

[zipster]

Been stalking the forums for years now but decided to make my first post based on a few observations.

So Greddy GR-3 5w30 is SL rated but not API certified.
Royal Purple 5w30 is also SL rated and not API Certified.
Now, Amsoil full synthetic 5w30 is SM rated but not API certified and Red Line 5w30 is also SM rated and not API certified. The same goes with Schaeffer’s 9000.
All are group 4 or 5 base stocks to my knowledge
Now, from what I understand, the transition from the SL rating to SM rating was the reduction of ZDDP. From what I have been told Amsoil and Redline oils did not meet the API specs because of extra amounts of ZDDP.

Wouldn’t that mean that these oils are all the same? I’m at a loss here. What am I missing?

One more question. I used to be a big fan of Mobil 1 5w30. I ran out of my usual Amsoil so went out and got some M1. It was very watery, made my engine sound funny and burned up about 2 quarts in 5K miles. What happened?

 

[chubbs1]

Most of them don't register for certification because of cost, others for their Additive packs. ZDDP (as I'm sure you know) has been reduced in recent years for pollution control/cat life. I very much disagree with them all being the same. The quality of the additive packages in those oils could vary greatly, whether SM SN etc. so they are not the same by any means. That is why they keep their proprietary info secret also...because they are all different in some way.

Now to answer your question about the M1, I have no idea what to say on that, it probably has more Grp. IV or V in it...lol

 

[oilboy123]

Minimal rating. Because they don't get the rating don't mean they ain't got the quality............

 

[gfh77665]

Originally Posted By: zipster
Royal Purple 5w30 is also SL rated and not API Certified.


RP is better oil!

 

[zipster]

My 2008 subaru calls for a SM rated oil. Would an SL be better or worse? RP is very cheap right now, so is greddy.

 

[tig1]

zipster,
You said,"M1. It was very watery, made my engine sound funny and burned up about 2 qts. of oil in 5K miles". I assume no other oil caused this condition.

 

[gfh77665]

Originally Posted By: zipster
My 2008 subaru calls for a SM rated oil. Would an SL be better or worse? RP is very cheap right now, so is greddy.


RP is SL, = Better add pack, better oil!

 

[Bill in Utah]

Originally Posted By: zipster
My 2008 subaru calls for a SM rated oil. Would an SL be better or worse? RP is very cheap right now, so is greddy.


PZEV model? SL is worst for your vehicle IMO.