Hi I have been reading with interest and thought I would let you know .we have been running a xc40 T4 R Design pro since March and have just covered 4000 miles,this is a T4 not the B4 by all accounts these are very similar and the dealer seems to think that the B4 should achieve 3-4 mpg on average more than the T4.as for our T4 we live in a rather rural part of Cornwall and average around 35-36 mpg with two 600 hundred mile round trips averaging 41mpg .the car is superb but if mpg is a concern or if at all heavy footed then it’s probably not for you as mpg can be considerably less if driven hard