Recently bought a mint alphard, 2004 2.4 very clean only 50k miles. was told it would average 30mpg on a motorway run at 60mph, Been driving carefully and even at 50mph on motorways, i have only covered 100 miles and almost half a tank of fuel is gone already! Does anyone know if there could be a cause to this? surely 200 miles with 60 litres of fuel is not right? Does the fuel gauge slow down after half way? any help and advice is appreciated!  

Driving in 3rd gear?

Check tyre pressures, and for brakes binding....

I get 320 from 60 litres average stop start driving and around 410 with motorways (3 litre)