I thought I saw this in the Intro manual, but nope, it was in Stu Ritter's 'E-Class Owner's Bible', page 149:

Engine RPM -------- Position ---------- Effect
==================================
Engine off ----------- Retarded ---------- Good starting

0-2,000rpm ---------Retarded ---------- Improved idle & cylinder filling

1,500-4,700 rpm ---- Advanced -------- Increased torque, reduced fresh charge loss

4,700-redline -------- Retarded --------- Improved volumetric efficiency

"The adjuster rotates the camshaft by 25 degrees between the default retarded position and the advanced position, relative to crankshaft rotation. The adjustment takes about one second to complete."