Keeping extra gas in the tank (aka filling up all the way) is like keeping a savings account - many people can't afford it. Depending on the country, the tank s

Keeping extra gas in the tank (aka filling up all the way) is like keeping a savings account - many people can't afford it. Depending on the country, the tank size and the price of gas, you can easily be looking at $100 for a tank vs. just keeping a bit in there to get around.