There seem to be a few threads on this already, and we've received some communications from Jason (the founder of GreenHybrid) on the subject, so I think it's time we had a stickied thread about it.

Anyone can sign up for an account and add information to the mileage database, true or otherwise. It appears that there is some erroneous information in there - impossibly low MPGs, etc. - and we're thinking of ways to lessen the impact of this erroneous data.

Here are a few things we've been thinking about:

1. Manual moderation of the database - this is something that has been done from time to time, in the past. An administrator goes in, looks for any data that appears to be incorrect (for example, a car getting 0.5MPG), and removing it by hand.
2. Discarding (or simply not processing) data that is impossibly high or low, such as that car that supposedly gets 0.5MPG.
3. Modifying the reports to include more information, such as the interquartile mean (the range of 25%-75%, so all the "outliers" are discarded.)

Manually editing the database is an OK solution, but it can be time consuming and will become moreso as more people start using the database. If you have comments on alternate solutions (such as #2 and #3 above), please feel free to post here.

Additionally, if anything in the database "jumps out at you" as being impossible, please feel free to post a link to it here, and we'll take a look at it. If everyone reports these problems in the same thread, it makes it a bit easier to track down.