i managed 42mpg over a 400mile round trip 
Don't know how you manage that!
My car got 870miles on the clock and can only manage less than 320miles on one full tank of Shell Superunleaded!
Saying this, I do a lot of town driving!
Hes a skill man i tell ya

, his old 3.2 litre, V6 R32 did the same aswell......................apparently

Free wheel the car, dont stop, avoid traffic lights and traffic jams and drive on downhill roads but never drive uphill then 420miles is very likely.

,or live in the Sticks to avoid all the above
At the risk of turning this into a fuel consumption thread, I have to agree with Rolfe. I can just about manage 40mpg when cruising very sensibly at 90kph, but any acceleration/stop & start driving sees the average plummet instantly to about 32.
^^^ about the norm id say to that quote