Interesting idea, and I like the idea of finding new ways to stay in competition with yourself to do better. We do have some issues with the EPA data that make me concerned about using that. For example, the EPA recently revised all of their MPG estimates with a new system, but they haven't released those new numbers in a developer-friendly format that sites like Fuelly can take and use. They only have the new numbers on their website.
So if we shift even more weight to the EPA numbers here, folks will be even more upset that we don't have the new numbers. Whatever part of the site we turn into a game, we have to make sure that playing environment is accurate or people will balk at the game.
We definitely don't want to start highlighting the best mileage with a 5 star rating or anything else on the site, and we've talked about that quite a bit. We even have a FAQ entry about it because it's such a common request:
Why don't you list everything in order of best fuel economy? Basically, once data entry becomes a game you can win, there will be cheaters. So we need to be very careful with incentives. Unfortunately, that means a little less fun in favor of a little more accuracy. It's a balancing act.
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