The Shell Credit card from Citibank is an excellent tool for those who purchase large quantities of fuel. My savings were 10% to begin with, and after the introductory period I saved 5% on fuel, credited to the following fuel statement. Over a year of driving 300 miles per weekend at $4.00 per gallon of gas, I saved over a hundred dollars in gasoline. If the card is paid in full after the statement is issued, the savings will help. If any substantial balance is carried over, the interest will cost more than the rebates pay back. Make sure to cancel the service after two years, at that point they being charging you a $20 annual fee.