Poor fuel economy occasional non start

[momorris]

Hi all
 Ãƒâ€šÃ‚      I am now the owner of a 1.9 n reg, recently the car has on occasion started then cut out instantly, this has happened twice and both when warm. Also i have now driven 30 miles and the petrol gauge has dropped to nearly a quarter used, surely this cant be right, what sort of endurance should i be getting from a tank?.