MDF vs hand cal variance with top offs vs fill ups.

Try to resist the tempatation to top off the tank. With a bladder system you risk overfilling and either:

A: Cause the bladder to over-expand then retract and push fuel back out which results in you standing in a puddle while gas spills out of the filler neck for 5-10 minutes.
B: You overflow into the emission system components and cause expensive damage.

 

I would never make such a suggestion because each situation is unique and only you can determine when you should fill up. I fill at 1-2 pips usually but I generally get 360-500miles to a tank. Filling up every 250 miles kinds sucks but I think running out of fuel would suck worse..... Unless a bus full of Hawaiian Tropic girls stopped to help you.

 

There's no reason to stretch a tank, except for (dubious) bragging rights.

I fill up anytime we're near our usual station and the tank is less than half. I fill till it does the auto shut off, and don't try for any more.

As far as calculated vs displayed mileage, our displayed mileage is consistantly optimistic by about 7%. I use it as a rough gauge as the tank progresses, but rely on calculated.