Average incorrect
 

avg MPG = 22.7, last MPG = 16.2, best MPG = 21.3

My average is better than my best? Sweet...

This can happen if you set your vehicle to track using odometer readings, enter trip mileage instead, switch to tracking with tripometer and then continue without editing that initial fuel-up.

So Fuelly was trying to calculate with both odometer readings and tripometer readings, and the combination wasn't working. I reset that initial fuel-up and reset your average so things should look better now.