QUOTE(abubin @ Oct 27 2020, 12:06 PM)
That oil looks
very dark. How you determine it is still okay?
You are indeed absolutely right in suggesting the oil looks very dark , judging from the wide spread area of grayish dark diffusion zone in relation to all other blotter samples in this thread of 10,000 km and below usage .
Now, why do I feel the oil is still okay ?
First the centre zone of 8 mm ( out of 28 mm minor diameter of right hand side lobe ) has not formed yet . It is not dark black and opaque , I see it as dark gray but still retains some semblance of transparency .
Before the first scenario occurs , the second condition of darkened aureole zone or perimeter ring of diameters between 8 mm and say, 10 mm zone or annulus has not formed at all on the right hand lobe , although it is emerging on the left hand side lobe .
This means agglomeration of excessively high levels of dirt/combustion contaminants has not yet occurred .
Next the annulus between diameters 24 mm and 28 mm is clean and quite clear, transparent and yellowish in colour indicating absence of dirt contaminants within the said annulus .
This means there exist some part of diffusion zone which are free of dirts and ready to absorb more, if and when more of contaminants quantity are introduced into the used oil through further usage .
Hence, my optimism in this 18,031 km blotter .
Having said this , I'm tempted to replace this 18k km oil if not because of the CMCO restrictions on my travel to Pandamaran workshop .
Note:Presence of water moisture as reflected by darkened jagged edge at the outermost zone that promotes corrosion wear does not worry me at the moment with 'spare capacity' to absorb further dirt in the transparent centre zone, aureole zone/perimeter ring and diffusion zone .
Also note there isn't any translucent halo zone beyond outermost zone to indicate fuel dilution phenomenon .
This post has been edited by zeng: Oct 27 2020, 02:25 PM