Well, to be fair, the OP asked for "opinions", not "facts."

And there is a wide variety of them here.

I don't see anything that I would consider a "bad practice", but there is stuff different than what I do.

I know that, in general, American oil change intervals are fairly conservative. As in a lot more often than is really needed.

The semi truck that is my work truck (Class 8 International) goes 50k between oil changes. Currently has around 300k on it, and I've run previous trucks well over 600k.

OTOH, there are folks who analyze their oil on a regular basis, and have found that some major brand synthetic oils will "shear down" from a 40 weight to a 30 weight in less than 5k miles. This has been discussed to death over in the Cayenne forum.

I do what I do because it makes sense to me, and makes me feel comfortable.
I'm gonna guess that most of us do the same.

Far more psychological than factual.

 

Here's a data point.

I had a case of multi-weight Quaker State quarts in plastic jugs that I moved 4 times over the course of about 15 years but never used. I can't tell you details of exactly what it was because I threw it away about ten years ago when I looked at it and found a quarter-inch of waxy stuff on the bottom of each jug. I meant to send one back to Quaker State but never got around to it.

I wasn't about to use it. I have a crankcase or two that's been sitting nearly as long but I'm scared to look.

 

From the AMSOil Q&A page:

 

I love facts! I'll muse about it: mineral-based oil is of course whatever hydrocarbons a refiner can find and mix together to meet a specification for viscosity, plus additives. Some could literally be wax (paraffin, in the US) - purposely or otherwise - that separates out and sinks to the bottom. I just read up on paraffin - your grandmother used it to can vegetables. 20-40 carbon atoms. It is refined from a byproduct of lubricating oil production called "slack wax". Maybe we can take some comfort from the fact that any paraffin (or similar stuff) in your oil pan will melt when exposed to engine heat and reform the original mixture. If that's what the "sediment" is.

 

Curt,

You are correct to say that paraffin wax is a by product of lube oil but the fact is the wax is removed from the mineral oil base stock so it is never in the finished lube oil to start with as solidifying waxes do nothing for the oil in cold climes. Exxon used to use a process called Ketone dewaxing in their lube oil refineries which if I remember correctly is a solvent extraction process using methyl ethyl ketone [MEK] as the solvent. The stuff removed is indeed a paraffin wax but it is not a paraffin [aka jet fuel]..

 

I change mine once a year. I am using synthetic oil and drive around 5k miles/year.