just a quick one, is the reserve tank on the 172 massive, as if I monitor the ammount of fuel Ive used and miles covered, then look at how many miles are left till the next fill -up, there doesnt seem to be enough fuel gauge left unless it stops on the R for quite a while.... im averaging about 41mpg since I picked it up, it this about right??, i dont go less than about 85mph on the motorway..