Hi Justine.
My Mito is not the Multiair version, it is the 1.4 Turbo Veloce. I would agree with all the others - I get similar MPG results as shown by the trip computer anyway. I have had up to 47 MPG, but you have to sit on the motorway at a very considered pace & work at it a bit. It seems to vary a lot with the weather temperature but in any case, the fuel gauge goes down extremely quickly & by a lot in my experience. I drive very sedately, but have been very unhappy with how quickly the gauge goes down. I don't know if it is because the car has a small (45 liter) tank, but I am forever putting petrol in the car.
I would not want to put you off buying this car, it is very beautiful looking, but there lies the problem. I bought mine in November & have regretted it ever since. It was supposed to be my dream car but I am afraid to say that this has not been the case. There are many issues in the quality & build of this car & in so many ways it is quite inferior to many other small hatch back cars. Do do your research & don't rush to get it. You would be far better to get a sporty Ford Fiesta - apart from the image of the Alfa, which is superficial anyway, the Fiesta is far more superior to the Mito. See if you could hire one for a week. Go & drive some other cars. I find the Mito uncomfortable, noisy due to poor sound insulation & very bumpy. You cannot get in to it on a frosty morning as the opening of the door relies upon the window dropping in order for it to clear the top of the roof channel - it is a pillar less window like the Mini. Mine literally freezes solid in the frost. Once I have managed to free it, I can't then close it without yet more fiddling around with deicer - it is a nightmare & can cause a long delay in leaving home in the morning. It is very prone to chips; make sure the one you are interested in has clear wheel arch protectors in front of the rear wheels as this is a particularly weak area for taking extreme chips. Do not buy a red Mito whatever you do - big paint problem with this colour. Make sure the steering & suspension are all sound - the car is not great at absorbing shock from the potholes in the road.
If I have put you off, I am sorry, but don't get one because you love the look of it, & you think you will be buying in to wonderful Italian heritage - expensive mistake. A Fiesta is utterly superior in every way.