Wow!!! That’s a lot of writing. As I said Shorter oil changes removes the floating crap from a belt that’s wearing out. It has nothing to do with good or bad UOA’s. Rubber and fiberglass don’t show up in UOA’s. Owners of this little 1.0t have to be concerned about the oil pump screen clogging. Nothing Bovine scary about it.
So if that's the concern for failure mode ... debris from the belt clogging the intake screen, they why not use a very inexpensive oil and OCI every 3k miles? Would that make the belt last longer? Would it make the belt life nearly infinite? What you're stating is that long OCIs increase belt wear, which in turn affects the belt "material shed-rate". Is that shed-rate linear? Is it parabolic?
In post #10, you indicate that belt life is limited by miles; "80-120k". That is a MILEAGE ONLY limit; has nothing to do with an OCI.
In post #14, you switch gears and say that your "feeling" is that shorter OCIs will allow the shed material to be flushed out.
Which is it? Is the OCI the determining factor, or the total milage the determining factor?
Show me some data that equates X miles of oil OCI to Y miles of belt shedding increase, and I'll see the connection. Otherwise, it's just hooey. I'm not saying you're wrong. What I'm challenging is the notion that the OCI determines belt life. Either way, I'm asking for you to back up your claim with some hard facts. ALL timing belts often should be replaced around 80-120k, even ones that are run dry outside of the sump; that's not an abnormal belt life.
I can accept that perhaps the "shed material" may clog the screen, but how is it that you're attempting to tie the OCI duration to that shedding event??? And
IF we accept the premise that the OCI is the determining factor, why not use a cheap conventional oil and OCI more often??? There are plenty of dino oils from all the bigs that meet the Ford oil spec for that engine (WSS-M2C945-A; and the updated equiv of 960-A). If "shed material" is a problem with clogging the oil pick-up tube and flushing the material is the solution, then why not OCI at 3k or 5k miles with cheaper oil? And
IF doing so will reduce belt degradation, does the belt life become 150k? 200k? Otherwise, the entire premise is just flawed rehetoric.