I wish you could get "gallon" credits. For example: Diesel is $2. 85 today. I purchase 100 gallons at that price. The next time I go to the same company, I draw from that credit, even if fuel is now $3. 05. Of course, if fuel goes down (HAHA!), you could pay cash or regular credit and not dip into your "cheap" gallon credits. Now if I could come up with $285 to buy 100 gallons of fuel. :{