i average about 42.6mpg 
Between 40 and 50 mpg with a mk1 1.2 75
punto 75 FTW
I get a little better than 17.5 Km/liter, 5.7 liters per 100 Km or about 49.5 MPUKG.
I'm not exactly a slow driver. We don't have as many radars here for the moment and I will use the airco if conditions warrant. Most of my driving is on motorways on longer trips. I do almost 3000 miles each month and wouldn't trade the diesel for any petrol engine.