since were on the topic, what sort of "performance" benefits will you see when changing your timing belt? When i say performance I mean engine power, engine efficiency, etc....

 

You shouldn't see any performance benefits, providing the old belt (and new belt) were/are under proper tension. The only real benefit of replacing the TB is that the engine will continue to run and you won't have the old one break and ruin your head.

 

Is that common? And what may be the cause of oil leaking from the cam/crank seals? I have this issue (I just found out) and it seams like every unknown problem is blamed on the heat... I live in AZ, and I'm currious if there could be a more specific cause.

BTW, I am at 82K (2000 S40 1.9) and am having the belt changed right now, due to the above mentioned issue.

 

Never Gamble with the timing belt, it's the most important job on the car, it got no specific time, it can getcracked in a un used car too,you wouldn't get away with the problems if it snaps or looses tension, might as well get it out of the way forpeace of mind.