OVERKILL
$100 Site Donor 2021
Right, just like a sample size of one doesn't make a sufficient rebuttal. This again comes back to "it depends", @The Critic cited a generalization of multiple examples, of vehicles he's worked on, and, while also anecdotal, certainly deserves the same degree of consideration as what you've presented.Varnish is "meaningless" was probably too harsh. I should have said "it depends" that's ambiguous and more pleasing.
Just because it's on the internet doesn't make it true.
Hyperbole isn't warranted. There are not thousands of vehicles on this site running drain intervals longer than 5K and posting up evidence. And there most certainly isn't a pool of people tearing high mileage engines down to check for things like ring coking for example.Sorry that my vehicles and thousands of others here on BITOG are throwing a monkey wrench into the "5k or less oci or else" theory that "The Critic" and others are trying to sell.
Again, a sample size of one, and, I'm quite certain you haven't pulled your rotating assembly apart, removed the pistons, and inspected the ring land areas. This is, at best, anecdotal evidence that this particular engine is reasonably tolerant of varnish accumulation.I check/test things for myself and get the firsthand evidence. When my evidence is to the the contrary, then comments like "The Critics" lead me to provide my experience so folks might do a little critical thinking.
I'm not a proponent of 5K intervals and personally run longer than that, historically using Mobil 1, which has kept those engines free from varnish. I've seen first-hand the result of lower quality oils changed at "reasonable" intervals (less than 5,000 miles) in several engines, that, upon tear-down, had significant sticking happening in the rings and stuck oil control rings. I've also personally offered up evidence of an engine maintained that way, and then run on Mobil 1 at longer intervals, liberating significant carbonaceous material from the ring land area, similar to what @wwillson is currently experiencing with his Durango, despite it giving no indication that this build-up was present (neither did my application).
A quality oil doesn't require 5K or less intervals to keep things clean and free of varnish. Varnish is a symptom of a lubricant being unable to hold contaminants in suspension and them plating out; it's indicative of the lubricant's detergent and dispersant system being overwhelmed. It is a symptom of the lubricant no longer being able to perform one of its key jobs, which is keeping things clean and preventing deposits. While you may not consider that a problem, it, by definition, is one. You, personally, may be willing to shrug that off as inconsequential, but it still needs to be qualified and understood for what it is.