One Texarkana couple apparently thought they had found a way to beat the high cost of filling their gas tanks, but the consequences may net them both some time in prison, according to federal officials.

Former postal contractor Paul Gregory, 40, and his wife, former postal employee Millie Gregory, 43, used two stolen U.S. Postal Service Voyager gasoline credit cards to charge more than $45,000 for gas purchases in Texas, Arkansas and Louisiana, court documents state.

Paul Gregory allegedly stole the cards, according to court documents.

The Gregorys began usi...