Avg Fuel Graph would be more useful if previous month a year ago could be compared. For example, I'm looking a February's average mpg, and I want to see what last year's February mpg is. Like my utility bills.
I think it would also be handy to be able to extend the line-dot graph backwards, like when viewing stocks and clicking on the "1 month", "3 month", "YTD" buttons to see the graph over time.