On 26-03-2021 18:10 Ed Pawlowski wrote:

Oh, I understand but conditions vary too.

You don't think manufacturers took all that into account when they often
recommended a filter every 2nd oil change under normal driving conditions?

Short trips in a very cold climate versus highway driving in mild temperatures.
Oil should really be tested and not just changed at some magic interval of one
size fits all.

I don't disagree on having your oil sent out after the fact for testing.

I can't see the inside of that cartridge filter, nor can I do a
flow test.

I disagree you can't see inside that cartridge filter since teardowns exist.
(1) Why do you think it has a pleated filter & which are the best?
(2) Why do you think it has an antidrainback valve & which is best?
(3) Why do you think it has an overpressure valve & which is best?
(4) Why do you think it has a gasket for engine mating & which is best?
(5) Why do you think it has many holes around the outside & which are best?

Not just about money too.

You had not yet mentioned a single decision that wasn't only about money.
I mentioned the specifications, OEM recommendations and the tear downs.

Clearly we think differently.

You seem to only care about money and convenience (and that's OK).
I very much care about what it is that I'm trying to accomplish.

I'm under the car, filter is right there, two
minutes and done. I'm certainly not going with an interval other than a
change time.

Most people are like you in that they don't understand what it is they buy.
They just replace it without thinking using any interval they feel like.
They probably don't even read the owners manual to see what it says.

And that's OK.
You can replace your oil filter on any interval you feel like doing so.

But I'm going to base my replacement on understanding what the filter does.
And I'm also going to base it on understanding what the manufacturer says.
And I'm going to base my replacement on choosing good filters to start with.

Having said that you're welcome to replace yours on any interval you like.
But if you ask me how I choose my interval then don't only bring up money.