Its worth checking the EGR. If its a bit full of crud the crud can prevent the piston opening and closing, in particular, properly into its seating. This can then trick the engine into sensing a fuel mix anomaly and higher revs may well result.
Using Bg44K and AR6200 does help with a cleaner burn and aids cleaning the top end. When I had my 220d i used a can of BG every 8,000 miles or so, and 5ml to 50 litres of fuel at each fill up. It certainly seemed better with it.