I only have an 11 gallon tank, so many of my fillups may be less than 8 gallons. I actually tie some together as I do partial fillups on occasion too.

An asterix next to the listing for cumulative distances under, say, 600 miles, and footnote to point out the small distance on which that 'average' was based might have exaggerated the normal variance of accuracy might suffice as take-it-with-a-grain-of-salt scepticism.
The 90 day average is a good method, except for those of us with large fuel tanks and fewer than typical number of driving miles. Ninety days may be only one tank of fuel for us, and as a result under some possible imposed miles threshhold.

Yeah, 500 or 600 miles would be reasonable, don't wanna peg it at 15K and have some folks taking two years to make it to the table, it would be discouraging.

Probably 5 tanks is a reasonable limit too, average is starting to settle down by then. Seems a lot of people "guesstimate" their first tank, then put real numbers in after that, if they continue.

Bumping this thread as I feel a bit like this is an issue too, and I'm nowhere near top 10.

IMO, a very simple and easy limit would make it much more fair without being very discouraging.

I would say that in order to be entered the person should need to have entered:

At minimum and in total (i.e. all entries added together must be this much or more):

400 miles and
4 gaslog entries and
20 gallons of fuel used

within the last 90 days.

For those concerned about ruling out people who drive very little or have extremely high MPG vehicles, 400 mi in 90 days is 1600 mi/year, and at 100MPG it would still only require 8000 mi/year to make 20 gallons in 90 days. That could be a little harsh on motorcycles/trikes, so maybe they could have a 10 or 12 gallon requirement? Or maybe there could be a 16 gallon overall requirement, if it would be too difficult to make separate requirements for different categories.

why not also have the top 10 4 wheeled vehicles and top 10 2 (or 3) wheeled vehicles as seperate entities so that motorcycles have their own competition. I know that they are split up if you click on the button, but on the home page.

that way you can have different standards for each. bikes that get 100 or so MPG also have tanks of about a gallon or so. this will allow them to continue to be in THEIR top 10 and give room for the cars as well.

I am no where near the top 10 so it doesn't really concern me but I figured I'd put in a word or two

That one might knock me out. I stretch my fills as far as possible. Some 3-month periods I only have 3 fills.

Wow. Maybe the best thing to do is to listen to everyone's complaints about what might disqualify them, and then use the smallest possible numbers.

What we are really trying to prevent is someone who only has one fillup or only a few miles from filling up the top 10. Oh, and to prevent people who are no longer active from clogging the list (but I think this one may be taken care of already).

Maybe a minimum TOTAL mileage? CleanMPG uses 5000 before giving a skilled/expert rating.
Maybe a time limit since the latest tank, like 6 months or a year?

I think a minimum total mileage of 5000 (or really anything higher than about 1000) could be discouraging to people who don't drive that much. It could take some people a year just to qualify for the listing...

Also, I think you should have to have a fillup in the last 90 days to qualify for top 10. Unless you've got some super huge tank on a geo metro or civic vx, you shouldn't be going 90 days w/o a fillup. You also shouldn't get to ride in the top 10 for a year by having a good set of fillups and then just not entering new data... When I click on the top 10, I want to know who the best are out of people who are still actively participating in the site. Maybe others feel differently about this...

Sounds reasonable to me. 1000 miles eliminates (almost) all single-tank entries.

An entry in the last 90 days also sounds good.