Here's my take on this issue.

If I'm not mistaken, you have the M103 motor. These engines have "short" timing chains. I recall reading post(s) here by techs who have indicated the timing chain issue isn't as big a problem for M103 motors as it is on the 420's that have "longer" chains. Even then, it may be more of a guide rail issue than chain. Don't know for sure as I do not own a 420.

I put over 300K on an asian 4 cyl engine. Never changed the timing chain. As Duke 2.6 mentioned, alot depends on oil change intervals and also, how sanely you drive the car.

__________________
Mike Murrell
1991 300-SEL - Model 126
M103 - SOHC
"Fräulein"