I'm am also proponent of the 10,000 mile oil and filter change. I have 2 300SDs with 200,000+ miles and both go 10,000 miles without adding oil. I use Mobil1 15W50 in summer car and Castrol Syntec 5W50 in the car used in summer and winter. The oil mileage improved from 3000 to 10,000 mles after I started using Castrol synthetic oil when I got the car at 160,000 miles. I don't know what was used before that.

Also, the oil leaks that were present, went away after I started using Castrol synthetic oil. So much for saying synthetic oil will cause an engine to leak oil.

I say Sheizen to the 3000 or 5000 mile oil change.

P E H