I did the same thing Craig. I was REALLY apprehensive about the 10,000 mile oil change interval (or longer). But I gave it a try and had an oil analysis done. My synthetic oil at 10,000 miles showed better oil analysis results than dino oil at 5000 miles. I'm convinced that 10,000 mile oil changes are fine on the 210 chassis. I'm still running dino oil in my 240D and have changed it every 5000 miles as the book recommends and will continue to do that.

Len
'99 E300TD 89,000 miles
'83 240D 345,000 miles original owner