I average 19mpg around town and 25mpg on motorways so I'm easily impressed by your 40mpg+ figures!
406 chap isn't light with the right foot but gets a good long run out of it so I can see how he gets 50mpg.
Makes me consider getting something similar to run around in, but I do so love the Delica for being able to transport 8 people or be a van for big things (like the 650l steel tank I've just bought), and having the 4x4 for sticky situations... well, she makes it worth the hassle of making fuel all the time!