What type of account (et, liability, revenue, or expense) would....?

Both of these would be expenses. They are both payments on accounts that are used to produce revenue. This probably has nothing to do with the question, but it looks like Joe is running some type of income tax scam. If he is expensing the amount that is delivered to the refueling station, then expensing it again when his trucks fill up with gas, he is expensing twice as much as he should be.