I see no point in cheating. I can get 15k/l on a low-side FULL tank (pump till trigger) and 15k/l on a squeeze FULL tank ( +2L after trigger) and consistent too on a cold fill ( pump car during cold weather and petrol tank is cold, +6L after trigger).
All above can span my mileage at 1/4 mark from 450km to 650km. Full tank can go 700km if i want.
Only thing changes for the fact u pump is the mileage u will get will increase gradually. FC remains same.
I would like to provide another opinion.....
When people "hump" their cars while pumping petrol in msia, its not because they want to "cheat" and get better mileage. Its
because the petrol there is cheap, so go all the way in liao, must ensure make their money "worth worth" as petrol in singapore
is expensive, so they hump their cars to pump that ~2 litres more to feel shiok. Maybe they are ignorant that their suspension
might be subjected to more wear and tear in the process. So i feel "humping" their cars while pumping petrol has got nothing to
do with FC.