Originally Posted By: TrevorS
I understand that dino oil is returning UOAs as good as syn would return, but does that:
1) Say anything about the relative longevity of dino vs syn?
2) Cover all the measures of oil performance that we should be interested in?
1- it says that a "baseline" would need to be established, and that would be done with a dino lube. To establish this criteria, one would need to run out a lube long enough that wear rates shifted (escalated) and condemnation levels were reached. Once those happened, then you could look at the OCI duration it took to get there, and then forumlate out an expected OCI duration of a syn, relative to the cost ratio. If syn cost 2x more money, then it would have to protect as well for 2x the distance.
2- No. A UOA does not cover every aspect of proper maintenance programs. It is a big chunk, but it is not everything. Some things can be inferred from the UOA, others not. Additionally, you'd want to perhaps to PCs, compression testing, visual inspections inside valve covers, monitor fluid consumptions, etc.
UOA are a direct view of lubricant health; they are an indirect view of equipment health. UOAs are the cheapest form of equipment "check-up" we have. We could do a tear down of an engine after every 30k miles, after each oil brand swap, and measure clearances and view for galling, pitting, scoring, etc. But that is cost and time prohibitive for most all of us. And so we rely on a UOA to indicate small shifts in wear, that would be precursors to larger events happening. It is important to note that UOAs cannot see particles generally larger than 5um, so an impending catastrophic event throwing large particles may never even been seen with a UOA. But then again, by the time your engine is in this condition, it's probably giving other clues (leaks, odors, noises) too.
2010_FX4 probably will not run out a dino all the way to see wear statistically shifting. That is his choice. But what he has proven here is that his self-imposed OCI duration is just as well served by dino fluids as super-premium syns. There was no tangible benefit to running PU over the MS5K; it was wasted money.