Hi i have a vw polo 2003 1.2, basically before i

hi, i have a vw polo 2003 1.2, basically before i bought this car, i thought my mpg would be more on a full tank of petrol, but i alway get an average of 194-197 miles on local for that, I wanted to find out whether theres a problem with fuel gauge, or miles meter. I always put £30.00 petrol in and that seems to be full by the looks on the fuel metre.
could somebody find out, and tell me what i should get out of doing local on full tank.