Once a year whether it needs it or not!You’re supposed to change the oil?
I sold a 2001 disco and replaced it with the gladiator. Working on the Rover every weekend got old after a while, and I didn't really trust it on long trips with the family. The gladiator doesn't have anywhere near the style points, but is such a better vehicle in every other way.Once a year whether it needs it or not!
Or get an old landrover. All you have to do is change the filter regularly because the oil consumption is so high (I get about 400-500 miles per quart) that there is no point - except maybe the aforementioned once a year whether it needs it or not. I never worry about shavings because nothing in old landrovers are close tolerance
I speak from experience too - have put 150K miles on a 2003 LR discovery. One of the most reliable vehicles I have ever owned. It reliably needs about $4K a year in preventative maintenance ...