Every 10k with full synthetic, FRAM filters say they're good for 20k, so imagine you can pull more mileage out of the money you spend. Modern full synth and engines can go 20k, a mechanic once told me
What you really want to do is fuck around on a car or learn about them, or drive them
Oil
Dump seafoam into your gas tank every 20k too
Replace 20% of your engine oil with this oil
Royal Purple is racing oil, corvette oil
Then this every 200mi just to be sure
Then this for a healthy engine
Then this for green emissions
Then Mobil 1 because engineers did a study, best oil for daily drivers they put it in fighter jets
Yeah no. Cardboard is not suppose to last that long anyway.