You probably don’t have a 4000+ pound truck with an average driving speed of 19 MPH over 6500 miles! It holds 6.5 quarts of oil too.
I do. Just under 6000 lbs actually. Averaging 19 mph makes my oil life monitor go off FAR earlier than 6500 miles so I change the oil accordingly.
I’ve owned this truck since new. Used Mobil 1 in it since the first oil change. Changed it whenever the oil life monitor (OLM) light came on. Towed a 9500 lb trailer with it 6-8 weekends a year. Commuted 90 miles a day for 5 years with it. Moved a portion of my home 1100 miles south in that trailer with it. The engine holds 6 quarts. Accrued 144,000 miles in -30 F to 100 F weather.
In that time, the OLM lit as early as about 3700 miles (short trips + towing) and as late as 7500 miles (nothing but that 90 mile commute). The engine never used even as much as 1 quart of oil in any oil change no matter how hard it was worked or as long.
Why? Because I used better oil than the manufacturer suggested and changed it when the manufacturer’s system told me to change it. That is easy to do, easy to remember and cheap insurance. Why do ANYthing else? Why try and second guess the folks who designed the engine?
And then you have the oil manufacturer who is trying to sell you LESS oil with their extended performance oil… It is selling a product to cheapskates who are risking thousands trying to save a nickel.
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Well at 340 hours (6460 miles at 19MPH) it would have been well overdue according to your oil life monitor. The M1 EP oil consumption could have been fine up to 250 hours (5000 miles at 20 MPH average) which is when it should have been changed (not withstanding their 15,000 mile claim).
I read that 50 * avMPG * quarts = oil change interval in miles. I hope I’m remembering the 50 correctly. So 19 MPG average * 6.5 quarts * 50 = 6175 mile oil change interval. Maybe I’m not remembering correctly and the 50 is supposed to be 25? I believe the formula is for conventional oil so 25 would give 3088 miles which would make more sense.
You can’t make that claim. The GM OLM (similar to most) does not trigger only on miles, it triggers on use profile. If that 19 mph was steady, not stop and go, not a lot of cold starts, and not towing a load, the trigger could easily exceed 6460 miles. As I stated, it did trigger as late as 7500 miles. Less than 340 hours, but so what?
Again, let the OLM do its job.
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What if you don’t have an OLM?
Then change it every 5000 miles. Done.
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I can’t. Can’t do it 
. Would probably be fine, though. Although all oil life monitors aren’t created equally. Toyota’s “maintenance reminder” is just mileage. I don’t remember how the F150 that I owned OLM worked exactly. Although you are probably aware.
On the Buick, in the near 10k mile OLM recommended oil change interval I referenced earlier, I was driving around 60 miles per day back then. Mostly interstate at 70 mph. Which makes sense concerning the long interval, I suppose.
Doesn’t matter , you would argue with it using your strange logic anyway .
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Somewhat off topic, but one reason I hesitate to trust OLM’s exclusively…I’m assuming the Ford OLM, for example, uses the same logic for a naturally aspirated V8 as it does for a twin turbo V6, etc. Surely some engines are harder on oil than others. But do manufacturers use different algorithms for different drivetrains? I kind of doubt it.
I’d be surprised if that was correct.
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You may be correct that it is incorrect! Boost pressure, etc may be factored into their algorithm. But I wouldn’t be surprised if it’s a one size fits all deal across a few different engine configurations, either.
And I wouldn’t be surprised if I was surprised 
He’d argue even if you agreed with him.
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The OLM on my F-150 (3.5L Ecoboost) is fairly conservative. I’ve only put a little over 7k miles on the truck in about 2 and a 1/4 years. However the truck is on it’s 3rd oil change. I’m sure that the fact that the truck is used locally, for mostly short trips, plays heavily into it. I would guess that the newer gen 2 and gen 3 coyotes with their ~8 quart and ~9 quart oil capacities tend to go a bit longer on OCI than the twin turbo V6’s with their 6 quart capacities. Less oil capacity + turbos = asking more of the oil, so it wouldn’t surprise me if the OLM logic is different between the engines.
It would be interesting to know if the OLM’s are different for the two engines. Or if they revised the OLM when the Coyote got direct injection. I suppose the engineers are the only ones who know for certain.
In your case the OLM may be going more off of time instead of mileage…? Doesn’t the Ford OLM timeout at 12 months?
Had to change my oil at 1300 miles to maintain warranty, Once a year, covid and retired year!
Your 19 mph average is your problem with you oil change interval. That means a lot of stop/starts or short trips.
Starting a cold engine produces a rich mixture and washes some fuel down into the crankcase. This both thins the oil and gives you a false sense of how much oil your truck is burning because it adds volume to your crankcase.
The problem is not as bad as it was before fuel injection and modern engine systems but it still exists.
That type of driving is not good for extended oil change intervals.
One of the reasons for shorter oil change intervals is to get rid of the contaminants that build up in the oil.
I think that no one should use extended intervals either in hours or miles that take them past the manufactures time interval in months.
It is false economy to spend less on oil and increase engine wear which is what you are doing by letting the oil go significantly below the add mark.
You also don’t have enough data points to reach any conclusions and for the data to be significant you would have to know how each vehicle was driven.
Aging oil can lose the ability to minimize friction.
Additive depletion, particulates, etc.
Rub a little of that long run oil between your fingers, then compare to new.
My last change?
3300 miles, 14 months, 170 hours
The oil life monitor on this 2014 Dodge RAM was down to a few percent remaining after the 340 hours.
What is your deal with hours ? The oil changes for vehicles are miles and months which is simple enough . Now public service vehicles might benefit from an hour monitor but not the ordinary private vehicle owner .
Letting the monitor get below 20 % is foolish .
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