I have been changing oil at 10K miles for 25 years now. My big trucks go to 20K miles

BTW as soon as I put new oil in one of my diesel engines it's black as soon as I start it.

I have to laugh at people who say it's needed at 3-5K miles becaue I have been proving otherwise for a long time. I change oil in over 25 vehicles and about 10 small engines. I buy my oil in bulk.