It's sensible to keep your tank low - vehicles are more efficient if they aren't hauling extra fuel weight. Aircraft operators have this down to a fine art.
I've heard its better to keep the tank near full in order to minimise the surface area inside the tank for condensation to form, this helping to prevent water from pooling at the bottom of the tank.
He's building synergy. It's a paradigm shift.
The law of conservation of synergy: synergy cannot be created or destroyed, only transferred to a different paradigm.
"The law of conservation of synergy: synergy cannot be created or destroyed, only shifted to a different paradigm." FTFY
If it's not in the computer, it doesn't exist.