Up till last friday my 2001 B6 A4 1.9 TDI 130 was returning 37ishmpg when used only in town and upto 50mpg on long runs at 75-80. Last friday i had a full service/timing belt/water pump at a local Audi specialist who has an audi computer (not vagcom) and i seem to be only getting 27mpg now??? although i have only done 100miles since the work was completed. does the car take time to re-set itself up? the timing before was slightly out (half a degree?) and now should be correct. Should this not make it better than before??? Any advice apreciated.