Well To try to answer the question as to whether I should change my oil more frequently than the factory 13K I had my oil sampled at 8725 miles since it was last changed. I had topped it up once with a quart.

The results are as follows
Iron 8
Alum 1
Copper 3
Chrome 0
Lead 7
Tin 0
Sodium 11
Dirt 5
Engine Soot Light
Fuel ---
Water neg
Solids none
Glycol neg
Visc 76
TBN 7

As best I can tell it is ok to continue to run with this oil but informed expert interpretations are invited.

__________________
MBlovr
'59 180 Dad's original
'59 180 Dad's 2nd one
'67 250SE Dad's last one
'59 220 SE My first one
'62 220SE Coupe second one
'89 190E 2.6 5spd third one
'06 E350 4matic (sold)
'10 E350 4matic