I get there is added complexity to the site, but it can be a very simple set of fields much like tracking the basics for fill-ups. I would like to get the TCO in one place and while there has been several comments early on in the forums I don't see any recent discussion. I just joined and without this feature, I am considering taking my 126 fill-ups elsewhere. Please tell me there is a way to enter date, cost, odometer and type of maintenance.
Sorry you got the wrong impression of the site. Fuelly doesn't track total cost of ownership, it tracks fuel economy. It's something we've considered in the past but we want to stay devoted to tracking fuel economy instead of creeping into other areas.
You can track maintenance with the Notes feature. You can add a description, odometer reading, and date. The idea is to record maintenance that could affect fuel economy. If you'd like you can record the cost in the description, but there isn't any sort of "total cost of maintenance" feature.