It is important to understand that offical fuel consumption figures bear absolutely no close relation to actual fuel consumption on the road in everyday use. Official figures are based on a rolling road formula in virtually laboratory conditions,and are intended simply to provide a basis for comparison with othe cars or manufacturers. So, for example, on a rolling road there is noair resistance to affect the consumption figures. The following link explains the process
Click on the "Fuel consumption figures explained" link
fwiw, I get around 40mpg with my TDi SE Stronic 177HP. This is a mix of urban and rural, gentle driving (Official figure is almost 50mpg). In general, real life is round 20-30% worse than published figures
The Honestjohn site has been campaigning for years for real mpg's to be made available, the site builds its figures from users posting their real experiences rather than the works of fiction required by the EU from the manufacturers. Real world seems to be about 20% less than official figures across the Q3 range.
I have certainly been impressed with the FWD 140 engine and manual gearbox- Stop Start doesn't get used a great deal now that I take a cross-country route to work, but consistently on a 21 mile drive to work, the car computer is indicating 55+ mpg.
Again, I used Motorways a reasonable amount too and a 30 litre refuel gives near-on360 miles of driving - I am driving down to Newquay next month, and can't wait to see how it does on a really long "cruise"
had my q3 140 tdis line fwd for 6months...average ful consumption done by me by filling up tank eah refill is 45mpg very mixed driving....best by me slow cross country trip in convoy 80miles total was 67mpg via computer read out fuel consumption muh better than my previous 2009 a4 avant 140 tdi
For the first 600 miles it averaged 45mpg, but this did involve quite a few long runs. We then went on holiday to Cornwall, a 350 mile trip each way. Setting the cruise control at a sedate 65 there and back resulted in 54mpg. Overall we did 1000 miles in a week and it averaged exactly 50mpg.