Originally Posted by d00df00d
Ah, okay. Thanks for clarifying.
ILSAC GF-4 is just API SM plus some other stuff tacked on. Same relationship between ILSAC GF-5 and API SN.
Also, ILSAC and API specs are meant to be backward-compatible. That means a GF-5 oil also meets GF-4, an SN Plus oil also meets SN and therefore SM, etc.
So, if you see a GF-5 oil, that means it also meets GF-4, SN, SM, etc. That means QSUD 5W-30 easily covers the SM + GF-4 requirement in your OM, so there's no contradiction between their spec requirements and their brand recommendation.
As to the "vagueness", maybe I'm misunderstanding your point (again), but I think what you're really seeing is that Hyundai intends for the engine to tolerate a wide variety of oils meeting very common specs. So, it's not that Hyundai is being obscure or noncommittal or anything; it's that they really do think (probably with good reason) that the engine doesn't care what oil you run as long as it's in the right ballpark. Makes sense for a mass-market engine meant to have easy maintenance around the world.
Does that help?
Oh, I agree that they are fine with running a wide variety of oils, which is partially the reason I started this thread as I was interested in different viscosities. It is/has been an interesting discussion, even if I didn't ask my question clearly. It's been a fun read.
That makes sense- I misunderstood the GF ratings. My mistake.
Ah, okay. Thanks for clarifying.
ILSAC GF-4 is just API SM plus some other stuff tacked on. Same relationship between ILSAC GF-5 and API SN.
Also, ILSAC and API specs are meant to be backward-compatible. That means a GF-5 oil also meets GF-4, an SN Plus oil also meets SN and therefore SM, etc.
So, if you see a GF-5 oil, that means it also meets GF-4, SN, SM, etc. That means QSUD 5W-30 easily covers the SM + GF-4 requirement in your OM, so there's no contradiction between their spec requirements and their brand recommendation.
As to the "vagueness", maybe I'm misunderstanding your point (again), but I think what you're really seeing is that Hyundai intends for the engine to tolerate a wide variety of oils meeting very common specs. So, it's not that Hyundai is being obscure or noncommittal or anything; it's that they really do think (probably with good reason) that the engine doesn't care what oil you run as long as it's in the right ballpark. Makes sense for a mass-market engine meant to have easy maintenance around the world.
Does that help?
Oh, I agree that they are fine with running a wide variety of oils, which is partially the reason I started this thread as I was interested in different viscosities. It is/has been an interesting discussion, even if I didn't ask my question clearly. It's been a fun read.
That makes sense- I misunderstood the GF ratings. My mistake.