Oil change interval

I've been assuming all along that the oil & filter change interval was 3,000 mi (according to the maintenance schedule), but I just discovered it's 6,000 mi. The dealer changed the oil & filter at 500, 3,000 & 6,000 mi. I decided to do my own at 9,000 and when I checked the owner's manual and service manual I was surprised to find the schedule was 6,000/12,000/18,000 etc.

I went ahead and changed them anyway, and I'll continue to do it at 3,000 mi. intervals (same as my truck). What's everyone else doing?