Hi Yuare ,

This 4500 km Zic X7 5W30 blotter has a light coloured and transparent centre zone (of about 8 mm diameter on real sample) indicating quite low level of large size or high density metal wear particles /combustion dirt .

The aureole zone /perimeter ring is slightly darkened and being very obvious which ,I am a bit concern on this .

It indicates signs of agglomeration of contaminants/dirts which you may want to monitor further such that it does not become further darkened and opaque . At the moment I suspect this is caused by 95% short distance cold running of the engine , hence internet suggests it shortens oil life theoretically .

The Diffusion zone is very light gray and transparent indicating quite low levels of contanminants .

There is no signs of water moisture presence but this 4500 km blotter seems to indicate a mild level of fuel dilution which may be explained by the rather low mileage of 4500 km over 8 months duration of operation .

Overall , I would say this Zic oil blotter at 4500 km is still in good and serviceable condition with plenty of life left .

You may want to take another blotter sample after 2000-3000 km or 4 month later and move from there .

By the way for a full synthetic oil , what is your typical oil change intervals so far ?

Attached is the Product Data Sheet of this Zic X7 5W30 ,

[attachmentid=10698167]

I found pdf TBN of 7.95 for a SN plus like X7 is abit on the low side where most other SN (without plus) that I came across has a TBN or 9 - 9.3 .

This lower TBN would supposedly shortens the  oil change intervals/ longevity of engine oils vs others of higher TBN values of similar Sulfated Ash ( Sa ) content .

It also appears to me its base oil is basically of the VHVI Group III type , probably without or very little of Group IV (PAO) or Group V (Ester etc) base oils .

Actually does 100% PAO engine oil exist in market?