I know the the mpg I get is going to be different every time, but I just thought that every time I fill the car the range should read the same. So if the tank holds 90 litres then the computer should read 1242 kms every time I fill the car. But in my local Topaz it reads 944 kms when full. In the Top Oil it reads 1044 kms and in the Esso garage it reads 1242 kms. I just find it strange that it reads differently between each garage.