Ok, this suggestion won't benefit most people, but if you own a vehicle where the odometer isn't accurate, it would be nice to be able to add an adjustment factor. I recently changed tires on my 4x4 to taller tires (33" tall instead of 31"). Since I don't have an easy way to compensate the odometer, all the readings in fuelly are now off. It's easy enough for a single fill up to do the adjustment in my head, but it means that the running average is off, and if anyone looks up my vehicle, it isn't accurate. I'd like the ability to simply add a 6.5% correction to offset the mileage.
That's an interesting idea. We'll add it to our list. Ideally we could allow people to answer a question like "Are you driving on stock sized tires?" If not, then we ask them to enter their tire size and calculate the difference to adjust the MPG.