http://www.audi-sport.net/xf/index.php?posts/2811776 For those that were interested in this. Preface, I did change my rims to 20inch also, but filled up my tank today and usually get about 24mpg per fill up. This fill up I got 17mpg for this tank with 80% sport ads city driving. I log all my gas mileage manually. Changed the XDS along with the starting vibration. Will set them back and see what the next tank gets but so far I've felt an acceleration difference ever since I've changed the XDS. Think this is definitely pushing more power to the rear first on aggressive starts causing the lowered mpg. Anyone else seeing this that have changed the vcd settings?