You guys should check out fuelly.com. you check in via text message (or log it from home) when you fill up with your odometer reading and how much you put in and it keeps some running stats for you.
Another thing you could do is buy a scangauge. Amazon sells them. It plugs into the OBD port on your car and gives you realtime stats.
The scangauge 2 also tells you a bunch of other stuff and can read and clear codes as well.
|