You can apply for a credit card affiliated with a specific gas chain that offers rebates or look for a general-purpose card that offers accelerated cash back rewards for gasoline purchases. For instance, the PenFed Platinum Cash Rewards Visa gives cardholders 5% cash back when they buy gas. This card is typical in that you do need very good credit to qualify, but the plus side is that you’re not locked into using any one particular brand.
The caveat: Depending on the issuer, some cards may have an annual fee. Many non-branded cash back cards don’t give you the extra rewards for fuel purchased at warehouse clubs. If you don’t pay off your balance every month, the gas savings will be canceled out by the interest you pay.