Pay plastic at the pump and save?

Rather than driving five miles out of your way to save a penny or two per gallon, you can generally save between 3% to 5% on gas if you keep the right credit card in your pocket. At $4 a gallon, that's the equivalent of 20 cents off per gallon. Even if gas goes back down to $3 per gallon, you are still paying the equivalent of $2.85 a gallon.

If you already pay with plastic, you can check your credit card statement to see how much you are paying per fill-up and go from there. If you are filling up every two weeks that translates to 26 fill-ups per year, so the amounts can add up quickly.