I once had a Dodge Dakota with the 3.9 v6. I changed the oil (dino 10-30) every 5k. When it got to 100K on the odometer, I started changing oil every 10K. The truck got real smart and started to change its own oil and because it had no thumbs, I would add the oil (about a quart every 1K). At 5K, Id change the filter. Went on this way until I could drive the truck no more mainly because it was almost a total rust out at 16 years of age. Got to 293K on the odometer.
The JD 750 I had for 28 years got 5 engine oil changes while I had it. It had 1650 hrs on it. I put roughly 50-60 hrs on it per year. It is now 32 years old and still going strong for the guy who bought it.
I think we change oil before it's done more often than not.
