First fill up- can this be true??

Why don't you people just believe the computer's mileage calculation? After all, that calculation is based on a close of monitoring of actual fuel consumption vs. mileage. When doing your own mileage calculation based on fill-ups, too many variables come into play and there is no consistent methodology that would work every time. The latter method just involes far too many assumptions: the pump is 100% accurate, the fuel warning light comes on at the same tank level every time, ambient temperature has no impact on the above, etc.

People used to calculate mileage using the fill-up method years ago when there were no alternatives. Now we have an accurate, viable alternative -- the car's on-board computer. Why would anyone want to go backwards in time when a better, easier, more accurate method exists on the screen right in front of you?

Why don't you people just believe the computer's mileage calculation? After all, that calculation is based on a close of monitoring of actual fuel consumption vs. mileage. When doing your own mileage calculation based on fill-ups, too many variables come into play and there is no consistent methodology that would work every time. The latter method just involes far too many assumptions: the pump is 100% accurate, the fuel warning light comes on at the same tank level every time, ambient temperature has no impact on the above, etc.

People used to calculate mileage using the fill-up method years ago when there were no alternatives. Now we have an accurate, viable alternative -- the car's on-board computer. Why would anyone want to go backwards in time when a better, easier, more accurate method exists on the screen right in front of you?