I think a lot of these 'X amount of miles per tank' is very ambiguous. How can you validate that that is the end of the fuel in the tank? I used to run mine on the ---------------- for ages, I even got an extra 45 miles on the ---------- once
Some people will risk pushing the DTE that extra mile, others will fill up as soon as the light comes on. A true test would be to run the car till it runs out of fuel. That would be a true validation. Any volunteers?