The only issue with that is that, 1. It only works with Exxon/Mobile/Esso stations. 2. It requires the gas stations computer system to be working to complete transactions.

I ran into that problem up in New York State when I was snowmobiling. A snow storm had knocked out the phone/data service in the area. Everybody had power, so they could still provide goods and services, but all transactions had to be done in cash. It was like that for a good three days, which really would have screwed us if I was only relying on credit/debit cards.