ZDDP
ZDDP
(OP)
I am a marine machanic and have received an oil report for a sample stating the ZDDP package has depleted in the diesel engine sample. I have never seen this on a report before. Can anyone tell me why this is important and what it is.
Thanks
Thanks





RE: ZDDP
much discussion about zinc of late.
RE: ZDDP
RE: ZDDP
how was the depletion of the zddp measured? i am not aware of any method that reliably measure the decrease in effectiveness, although an atomic absorption emission measurements interpreted by a skilful engineer might accomplish that.
RE: ZDDP
RE: ZDDP
Franz
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RE: ZDDP
The pro is less cat and O2 sensor poisoning. Especially important during breakin. The con is less protection if the engine is not operated for long periods of time.
In the end, the new oil will prolong emissions durability and the net effect will be longer engine life since there will be less unburned fuel reaching the crankcase.
Next time you are at an auto parts store take a moment and look for GF-4 on the label. It is not so common but GF-3 is everywhere. Only a few weights of mobil one are GF-4. I run it in my GMC Denali and I would expect better fuel economy over the long haul since the 02 sensor is not likely to deteriorate as rapidly as is the case now.
RE: ZDDP
most oil sample analysis programs use some form of emission spectography to detect wear debris - the most prominent type used being ICP, whereas AAS is far less used because of the fact that interpreting the results is rather difficult. Even if AAS is used it is difficult to discern between "fresh" zinc compounds and compounds that have somehow been used and therefore lost their effectiveness. So the question as how the loss of effectiveness was measured is still a valid one.
in most analysis programs the amount of zinc compounds is measured, which as such, give no clue to their effectiveness or the changes therein.
RE: ZDDP
Depleted compared to what? If unit averages it probably means you used a low phosphorus specification oil while most of their database didn't. Low P formulations are usually supplemented with other AW chemistries, so this doesn't automatically mean inferior performance, but if you are concerned and your equipment doesn't recommend it then you may choose to stick with engine oil based on older, typically higher P specifications.