The best thing you can do to minimize wear to the pads on the Vario-Cam engines (2000-2002), besides the obvious maintaining oil quality, is to avoid cruising in the changeover rpm range of 2200rpm- 2500rpm
They usually wear this much after 40K to 80K miles & cause the changeover to be less smooth enough to see a power drop on a dyno chart @ that rpm. Eventually the pad can deteriate enough to crack & break causing excessive camshaft timing deviation & Eventually chains coming loose. So it's a good idea to install the new more wear resistant wear pads before 80K miles.