[dremd]

I know I've said all of this before in this thread,

Oil basically never breaks down from wear, if you are shearing your oil you have serious issues.

Additive packages DO wear, this is why for extended drain intervals you need a TBN.

Particles DO wind up in your oil which cause wear, this is why you need a spectrum analysis of used oil, or at least a filter that picks up "all" of the wear sized particles (say 5 micron absolute as a minimum).

Water DOES get in to oil which causes acid formation in your oil which corrodes parts, breaks off bits which contaminate your oil and wear your remaining parts. This is why you need to verify that there is no water in extended drain oil. Emulsifiers hide water in oil up to around 15% to the human eye / feel test. Labs can detect down to 0.1%.

If you can see contaminates on a full flow filter you should start planning for a motor / overhaul.

If your full flow oil filter is plugged, your motor probably is already knocking.

Fuel DOES get in to oil, it reduces lubricating properties, and tends to break down the lubrication abilities of the oil. Tight clearances, appropriate mixtures, and proper thermostat temps keep this way down but it is worth checking. diesel in oil isn't noticeable until 20% and wear starts becoming noticeable around 5%. Labs check for fuel dilution.

Smallest particle you can hope to feel is around 50 micron, any particle causes wear, the smaller the less, but oil loaded with 50 micron particles is like a slow smooth grinder.

VW PD engines are known for being picky about oil and are poor engines to do extended drain intervals, expect early cam failure (worn down lobes) along with injector issues.

I've been reading comments in this thread, and have decided to unsubscribe, good luck to all and I truly do wish you a great engine life span.

For WAY better info than I can provide, send in an oil sample to a lab, and visit bobistheoilguy.com