OEM's don't give a damn. They're after the "Lowest cost of ownership" on paper. If they tell you you can run it 100k before oil changes the odds are in their favor it will make it out of warranty before you see parts failures. The pencil pushers in the office at a fleet will do the math and figure what that would save in the life they will own that truck and jump all over it. However after the warranty is up and you see what those long intervals have done to parts what have you saved? If your a big fleet and buy 500 trucks and only keep them for 400k miles then by all means run it 50k. But the next guy that buys it or the owner operator that keeps truck 1mil is going to pay for that decision.
I've heard of big fleets here changing oil until they get 300k and never changing it again. They might run them 100k more and never once pull the plug.
Oil samples are like a fat guy getting on the scales. If it comes back with high copper content what are you going to do about it? If the answer is "probably nothing" then what was the point? In the big picture of owning a truck the cost of an oil change is trivial. Would do most of these guys good to crawl under it once in a while and see what is going on. Most guys spend more time at the buffet than on a creeper.:hehe:
I've done the math many times because I get tire of people claiming oil is a cheap overhaul, it's not. Oil changes on big trucks are expensive. Why throw away good oil? If you plan to keep the truck and overhaul it anyways then you wasted a lot of money. The difference in the 250hr oil change versus 1500hr on an older engine that would run to 25,000hrs, with $150 oil change costs is over $12,000.
Again if you will keep the truck and overhaul it anyways, why is a million miles the mark to hit? You probably won't be running it long enough after overhaul to come close to wearing it out. Even if extended drains were causing slightly increased wear, and you overhaul 100k sooner what's the big deal if your cost of ownership is lower. Done right, you shouldn't have higher wear anyways.
Now if you are planning on selling the truck at 950k and it has to make it there without and overhaul, are you getting that extra 12k worth out of it? What if you decided to sell it at 850k instead? Lower miles gets a slightly higher price and you have a lot less in maintenance invested.
I'm not trying to be a pencil pusher, but some people seem to get emotional about oil changes and engine life and ignore the numbers which really do matter regardless of if you have one truck or one hundred.
If you are only looking at wear metals on a UOA your throwing your money away getting one done in the first place because like you said, there's nothing you are going to do about it. TBN and even better would be TBN versus TAN, is the number that is most valuable on there. Simply put, it's telling you how much life is left in the oil. Plain and simple. Looking at silicon can show a leak in the air intake, bad air filter or an oil filter that is maxed out for that drain interval. You may need a different filter, an extended service one or it just may need to be changed before the oil. Fuel dilution is another helpful tool as is being able to see traces of coolant. The actual wear metals I never really care about, they can be misleading and they can scare people into tearing things apart for no reason.
Without a UOA you can't know what's going on with your oil, but a UOA is only as good as the person taking the sample and the person interpreting the results. It's also just an added cost if you never do anything with the info.
The oils are made for long drains, the engines are made for long drains, put it to work for you. The 10-15k truck oil change is like the 100-250hr tractor oil change or 3k mile car oil change. Long gone, even though many won't move on.
More and more OEMs for off road equipment are moving to scheduled sampling instead of scheduled service. You pull your sample, send it in and they tell you what to do. They don't even print a general recommendation in enough of the books anymore, everything is analysis based. The larger the equipment is the more common this is.
Delo has a lot of info on extended drains and what their test fleet engines look like after running them for long time periods. Yes it's promo material in a way so it's biased, but why would an oil company want you to buy LESS of their product? They aren't promoting a premium product over their base product, their doing this with their whopping $10/gallon oil. Why would they encourage long drains when they have a guarantee /progressive damage warranty? Maybe they deny every claim, maybe nobody knows about it, maybe nobody has ever needed to collect on it. I dk.
One thing no amount of data, numbers, science, and hard facts can overrule is a person's emotions. If at the end of the day it still helps them sleep at night to change early then go right ahead.
I do find it interesting the number of people that boast about their short OCIs yet don't have a clue what their coolant is doing. Must get too focused on the oil, but ignoring the coolant can wreck the motor just as fast as anything. Using the wrong coolant, not testing it properly and fully, not testing it to begin with, using the wrong additives, or even just adding additives without testing for some reason. I don't know the number of times I've run into people running OAT ELCs and they are still running coolant filters full of SCAs just because. I'm not criticizing anyone when it comes to coolant, it's a nightmare to understand, but it's not impossible and a little research in the right place goes a long way, but if you never step out of the bubble you never know. The worst is the people just running fully formulated automotive coolant.
To each their own. I don't like changing things all the time especially before it's needed. I don't replace tires at half tread why replace the oil at half life? I'm not out buying expensive oil and bypass filtration systems with the hope of running 250k on an oil change, just wanting to get the most out of a dollar and not spend my days changing oil for no reason when I could be doing better things.
That's just my opinion though.