Yes, I used to keep a similar chart. I had set to calculate a running average mpg as I added each fill-up to the list. It's a really good way to keep track of your gas mileage and to see if there are any disturbing trends. I haven't looked at my old chart lately, as it is on one of my older computers, but I remember also keeping a notes section to the side so I could note whether it was a city or ross-country tank, or hot or cold, etc. Thanks for sharing your chart, I will have to go look at mine (in Lotus 1-2-3, I believe).