Originally Posted By: shpankey
Originally Posted By: Audi Junkie
Originally Posted By: Spyder7
Originally Posted By: Audi Junkie
Spyder, wear spikes on fresh oil and is reduced in rate as the oil ages. That is the data from the 3MP study.
Gotcha. New one on me, but the source is credible and its good info to know.
-Spyder
You're not going to insist I "PROVE IT!"
Audi's right. Here's a good case study that shows this idea in action. Notice how the wear numbers start dropping after 3k miles. It's funny when you think about it really. All these years everyone thinking 3k mi OCI's was actually more than likely causing more wear than it would have had they ran it out. Anyhow, link...
LINK - click me
An interesting piece from the Mobil study you linked to:
"More than anything, what this shows is the incredible effect top-up oil has on the longevity of the motor oil. Even with the minute amounts of oil we added over the course of the study, we extended the "age" of the oil by 8,000 miles compared to adding no oil at all. Indeed, the filter change at 12,000 miles refreshed the oil so well that its corrected age actually remained below the 12k sample's corrected age for almost 3,000 miles! It's no wonder extended-use oil change schemes demand frequent filter changes. The top-up that follows the fresh filter is practically a time machine for your oil."
I'm still digesting that. Where mine burns and therefore gets considerable top up oil, it has me wondering how often I should change oil & filter vs just changing the filter itself and the oil only rarely. Nice link btw and thanks for posting that.
I still need some time to digest it, but that said, it seems to support the assertion that 20k is too long for a filter to maintain optimum efficiency (I'll add a caveat that excludes anything designed to be used that long). A filter designed for 15k (say the M1 EP) may become more efficient after the first 5k or so on it, but as you approach and pass 15k, I think efficiency would decrease.
This is a lot of supposition on my part and I'll admit that. The new oils and filters available have no doubt changed the rules, and I only defend it in the case of those who rely on the OLM to falsely assume that the oil level is correct, and never do the things that were 'common sense' once upon a time, like checking tire inflation, oil level, and fluids when you filled up. As the vast majority of us here on BITOG do this stuff anyway, I consider 3k or 3 months a moot point here. We all know the difference and, the only thing we debate is how far beyond 3k to go, or what oil is better suited, etc.
-Spyder
