How can two teen brothers share a car and be fair when paying for the gas?

Question

My second son is getting his license soon. His brother has been driving our third car and paying for his own gas. His brother will be going to college so 2nd son will have the third car to himself most of the time. But when older brother is home from college how do they share the car and pay for the gas themselves and be fair about it?

Answer 1

make them split the first full tank then have them each refill it completely each time, that way they KNOW the other one put gas in. if they don't, they have to give the other brother extra money for next time or they get the car taken away for a certain amount of time.

Answer 2

That's easy - Leave it empty.  One of them will, so just makes sure the other one does it too.

This is so easy ( and frankly, necessary, if you're dealing with my brother) that I'm surprised so many folks gave more complicated answers.

Answer 3

how mature are they? is the car a gas guzzler? i say it can be done. or you regulate the gas that goes into the car. or do it like the rental companies do it. the car is to be turned over with the same amount it was recieved. no harm no foul. trust your boys.

Answer 4

when each one is done driving it they have to fill up the tank or they don't get to use it when it is their turn again.

Answer 5

marks the miles each one drives each time they drive and calculate that into how much gas that would use and pay up :)