Yes, mines the same. Just done a round trip isle of wight/stockport. Managed 620 miles before fill up but it counted down pretty quick for the last few miles. From the trip reading 17 miles left i worked out that there was still just over a gallon left.
can't comment on the q5 as it hasn't been delivered yet, but i've had the same happen with our current A4 (2006 diesel) and then the TT (2003 petrol) i had before that. So it appears that it is still happenning with audi's new cars as well.