Originally Posted by 280EZRider

Thank God tangofox007 noticed the confusion in replies in this thread. The M617, as well as many MBZ engines, has no tappets, lifters, or push rods. The cam lobe rides directly on (under, actually) the rocker arm, which in turn pushes directly down on the valve (stem). So as far as oil type is concerned, valve lash is of no consequence.

You owner manual will have the frequency for valve adjustment.