IIRC my old one did about 25 to the gallon ish. I never bothered calculating it properly.

I could brim the tank £55 and set off from Preston to Bristol (200 miles) and get there with the needle reading half a tank. The van was a little slow though so I wound the fuel pressure up on the injector pump which meant that if I held it on full throttle for the journey, it drank fuel but keep it at a steady 70 - 80 and it was the same MPG.