one big reason for going diesel is depreciation - my oneD has held on to it whole difference in price over the petrol version. it still lists 1000 over the petrol on the second hand stand. No reason to assume the new one wont be the same. For me, the reason for trading up is two fold - i bought max in a huryy - never regretted it, but now i want to spec it myself - though wont be going mad. aircon, half leather, mfsw and armrest are as mad as i get.