I have no stake in either method, but a few mediating comments...
Yes, this is indeed "GasSavers.org" -- saving gas; however, my take on the site focus is that it's a discussion to help the community of members modify vehicles and driving habits, so that you are saving gas in what you drive, no matter how far you have to drive it. A few points against the weighted average:
- Many participants have a long commute
- Public Transit or HPVs aren't available or practical for all participants
- Fewer gallons calculated, yields a higher rate of error
I agree that it is a noble proposition to reward those who use less fuel, but the heart of the competition seems to be that of "How high above the combined EPA value you can get out of your vehicles".
Perhaps an honorable mention or special award could go to:
- The Least Amount of Fuel Used, and
- The Most Improved Reduction in Number of Miles Driven
Just some thoughts...
RH77
EDIT: I think I see where this was heading (2 directions possibly). First of which was the above, secondly, the most efficient participant could do most of the driving, whereas the others could hit their minimum 3 gallons. But how would you rate the higher-miler inversely?