It's most likely the gauge, not the car, they're pretty poor in 306s in my experience at least! £20 isn't half a tank, closer to a quarter tbh!
But that doesn't sound far off anyway, about 25mpg, that's pretty much what I was getting in the GTi6.
But that doesn't sound far off anyway, about 25mpg, that's pretty much what I was getting in the GTi6.