Found this: https://theconversation.com/can-you-save-money-at-the-bowser-by-only-half-filling-the-fuel-tank-36260 https://theconversation.com/can-you-save-money

Found this: https://theconversation.com/can-you-save-money-at-the-bowser-by-only-half-filling-the-fuel-tank-36260 https://theconversation.com/can-you-save-money-at-the-bowser... Very nice calculation. The results were that by filling up two half tanks as opposed to fully topping off one can get an extra 3.5 kms, albeit with a time penalty for going twice to the gas station. Hardly worh it as just making the round trip to the gas station would probably eat up those kms. To this I would add the wear and tear on the car by having it run longer with a nearly empty tank, something which is not recommnded.