Originally Posted By: JohnBrowning
Long ago I commented on how the Asian OEM where concerned witht he drop in phos but could care less about the Z in ZDDP. No one got it at the time the article does a good job explaining why the P in ZDDP and the sulfur which I long ago said I missed where so important. ZDDP is just a an ends to a mean.A lot of Aisin OEMs still do not use rollers in their valve trains.
Yeah zinc is probably just there for bonding properties for the sulfur and phosphorus, and maybe anti-oxidant effect. What I found confusing was the article seemed to suggested sulfur was doing most of EP anit-wear effects, but then it went on about the phosporus level mostly. Onerthing I am confused about is does the sulfur creat a lot of sulfated ash? I use to hear about "ashless" oil, but don't all oils have some ash levels, and if they didn't they couldn't have zddp?
The article also says that weights heavier than 10W30 and dual rated HDEO are exempt from the zddp limits, but they are still SM rated. Can anyone verify if HDEO still have more zddp than non-HD SM oils?
Long ago I commented on how the Asian OEM where concerned witht he drop in phos but could care less about the Z in ZDDP. No one got it at the time the article does a good job explaining why the P in ZDDP and the sulfur which I long ago said I missed where so important. ZDDP is just a an ends to a mean.A lot of Aisin OEMs still do not use rollers in their valve trains.
Yeah zinc is probably just there for bonding properties for the sulfur and phosphorus, and maybe anti-oxidant effect. What I found confusing was the article seemed to suggested sulfur was doing most of EP anit-wear effects, but then it went on about the phosporus level mostly. Onerthing I am confused about is does the sulfur creat a lot of sulfated ash? I use to hear about "ashless" oil, but don't all oils have some ash levels, and if they didn't they couldn't have zddp?
The article also says that weights heavier than 10W30 and dual rated HDEO are exempt from the zddp limits, but they are still SM rated. Can anyone verify if HDEO still have more zddp than non-HD SM oils?