My three week old E63 has a sticker on the windscreen stating the running in instructions, something like 85 m.p.h. max and 4500 r.p.m. max. for the first 1000 miles then slowly increase.
I have always run in new engines, whether a Vauxhall Corsa or the E63, and I just use some common sense - i.e. do not over rev the engine and do not let it labour at low revs in the wrong gear. If on a long run on the motorway I alter the speed from one junction to the next by 10 m.p.h., moving between 50 m.p.h. and 80 m.p.h..
From 1000 miles onwards I do not worry too much, but I am not a fast driver.
I do not really see what difference the mode would make, except the engine will rev higher between gear changes. I have left mine in Comfort, which it seems to default to every time the engine is started, and it still goes like hell if that is what you want.
