Doing Co2 searches,just to make sure the tax people have everyone's coding right. My car (140bhp 2.0tdi DSG) has a CO2 rating of 159,which tallied with Audi's rating when I bought the car. I note that,according to Audi,the CO2 rating is now 151 for the same engine and gearbox combo. The manual version is 148. Both Co2 ratings are a good bit lower than when the 140bhp was launched. Why ???