It would be nice if you could add a "projected 2013 cost analysis" button next to the 2012 cost analysis button using the previous accumulated average costs/miles, etc... I know I can do the math myself, but it would be cool to have it available so you could see the projected cost for 2013 using the average of your accumulated stats.
Everybody on this site is obviously concerned with their gas mileage or they wouldn't bother logging in. I think if we can see the projected estimated annual cost of fuel consumption live, in black and white, it will encourage all of us to squeeze that little bit more out of our tanks.
For example, if you drive 200 miles a week and you average 20 MPG, you're consuming 10 gallons a week, at 3.50 a gallon, equaling 35.00 a week in fuel cost. If you change your driving habits a little and get two miles a gallon better on your next fill-up, for the same 200 miles you'd only use 9.1 gallons, or you'd go 20 miles more between fill-ups. Broken down by fill-up, that's impressive, but if you could look a year into the future you'd see your estimated fuel consumption drop by 47 gallons, or about 165 dollars, that would be really encouraging!