One gallon is equal to 3.785412 liters/litres.

So 128 cents per litre would be about 485 cents per gallon. 140 cents per litre would similarly become 530 cents per gallon. (I'm keeping it as cents because I'm not sure if a cent is also a monetary unit in Australia, so I don't want to translate it into U.S. dollars.)

If "cents" does indeed refer to U.S. pennies, then the conversions are $4.85 and $5.30, respectively.

America feels nice when you think about it that way.