It appears that the "Top 10" are probably the most queried vehicles, not the top 10 most fuel efficient as one might guess at first.
While this is very handy, a list of the top 10 most efficient vehicles should also be listed. To reduce outliers, only vehicle models with more than say 30 vehicle entries and more than 10 log entries.
Thanks for the site, it's a useful tool for comparing!
I think the site developers are reluctant to do things like this as it encourages competition and perhaps makes some people want to cheat and input inaccurate data. The same reason you can't organize cars in order of economy.
Bones, thanks for the feedback. You are correct that the Top 10 simply shows the make/models with the most vehicles in Fuelly. Draiglag is also correct that, in the past, we have strayed away from features that would encourage competition. We'll be working on some new statistical methods to better understand our data and with time we'll probably have some new features so you can see how cars rank in their category along with some other grouping/ranking tools.