I am a fan of Mobil1 so don’t misunderstand me, but accelerated oil tests like this one that XOM presumably would have had to use in order to get results in a reasonable time, always show remarkable results regardless of oil used. The cars are run so much, usually ‘round and ‘round on a track, that the oil only stops circulating at oil changes and the engine is never shut off long enough for it to run off internals, never accumulates any water and never even experiences starting a cold engine.
I remember talking with a limo driver in Toronto way back in the early 1980s. He said their Buicks’ engines lasted 300,000 miles, an unheard of number in those days... and that would have been on conventional oil. He said they never turned them off. It was a vivid demonstration of how much engine wear occurs on startup vs. running.
Further evidence of the importance of oil flow at all times is provided by Honda’s choice of oil filter specs. I think we would all agree that Honda knows a thing or two about engines, yet the oil filters they specify, put their name on and sell catch a lot less dirt in first pass tests than higher line Frams. They also do relatively poorly at catching the smallest particles, yet their engines are known for lasting longer than most of their competitors.’ Numbers like these suggest that Honda’s own tests might show that engine health depends more on a quick flow of pretty well filtered oil at start up, than on oil having every tiny speck removed as soon as possible regardless of how much it might delay the flow of filtered oil. That would jibe with the limo driver’s report. So we might be barking up the wrong tree looking at first pass filtration percentages vs. flow rates.
One thing we do know for sure though, is that engines that are almost never shut off last many more miles than those that sit.