Oil filters are dead end filters that will eventually clog. The efficiency quoted on their carton is for a single pass through, because they have already started the clogging process.
The 'suspended contaminants' mentioned in another post are from the wear and tear oil goes through in the high stress environment of an engine. Outside sources, like sulfur content of the fuel, also play part. Their growing presence in the oil is why it turns darker shades.
My car had a cartridge filter that was easily changed from the top. No messing with jacks, crawling on the ground, or blind reaching to swap it out. So I swapped it out before actually changing the oil to see if it had any visual impact on the old oil.
Since it lighten the oil's color, that tells me the darkening was mostly due to those suspended particles, that they aren't simply too small for the filter, and that the old filter had the bypass valve open at some point prior to the oil change interval.
As to these contaminants settling out and blocking things, I no concern for that happening. There is the flow rate and pressure of the oil pump to keep things moving, and the oil itself contains detergents. Not only do they keep the particles in suspension, but they also keep those particles from clumping together to form sludge.
The real threat these particles pose is that they form acids when mixed with water, and it doesn't matter if they are trapped in the filter or not. But along with the detergents, the additive package in the oil also includes compounds to neutralize acid that forms.
As too early oil change on a new car, it is just a placebo. Modern manufacturing means the parts fit better when assembled than it was in the past, and the engine gets run as part of the QA process. If the manual doesn't call for an early oil change, then the car doesn't need it.
I did just the opposite with my van. It called for oil and filter at 5k miles. I used synthetic oil and changed the filter at 5k with the addition of 1 quart to replace what was lost with the filter. Oil changes at 10k. Saved a ton of money compared to straight 5k intervals and it was still perfect at 187k when I retired and sold it.
Very few cars get sent to the scrap yard because of an issue arising from a lack of oil changes. I suspect many that do go that way still run, and they are just worth more for parts and scrap than the effort to keep on the road.
The US is switching to ultra low sulfur gas, unless Trump cancelled it. Manufacturers should increase the length oil life when the roll out is complete.
I tend to follow the instructions on the owner's manual for all my vehicles.
In my 1993 Impala that means doing an oil change every 5000 miles, while with my Peugeot 3008 that means every 10000 miles...
That should be your golden standard.
Of course then there's some variability depending on your circumstances...
This guide here (https://roadologist.com/ultimate-guide-to-motor-oil/) sums it up quite nicely.
- if your vehicle is new, or
- if your driving mainly consists of sessions of 20 minutes or more at fairly steady speeds (as opposed to stop-and-go traffic)
then you can probably increase a bit the mileage between oil changes without consequences.
- if your vehicle has more than a couple of years, or
- if your driving mostly consists of shorter than 20 minutes sessions or of stop-and-go traffic, or
- if you frequently drive off-road or in particularly dusty/sandy environments
then you should definitely consider decreasing the time between oil changes, and perform more frequent maintenance (e.g., every 3000 or even 1000 miles).