The oil monitor doesn't specifically measure the "quality" of the oil. I mean specifically, it's ability to protect the engine. It uses several metrics/algorithms to tell you when it thinks an oil change should occur. The number of engine hours on the oil, the number of engine hours/miles on the engine at certain speeds, the length of time since last oil change etc., etc. And the list goes on.
I dislike oil change threads simply because everyone has an opinion on intervals, oil brand, and filters. There simply is no consensus and truthfully, no one answer is right for everyone. There is little that can be said to change another's mind on what's best for their engine.
Often claims are made about how far their vehicles have gone using extended change intervals or specific oils and filters. Yet, those making the claim seldom take into consideration what a small sampling they use to make a very broad recommendation to others.
I personally believe that the manufacturer recommended change intervals are a joke and best suit their interests and not the long term vehicle owner. Moreover, researching on the internet will no doubt support one's beliefs, regardless of what that may be.
This video is a good watch, albeit a bit lengthy. If you want the short version, take a look at the 26-minute mark. Lake Speed Jr. is a bright guy when it comes to automotive lubrication, he has a ton of videos out there.
