I recently added a 3rd vehicle on my fuelly account and it is not recording the fuel ups correctly. When I look back it doesn't show the correct miles on the dashboard of my account. It also doesn't appear to be recording the MPG for the 3rd vehicle. This is the 3rd fill up and none of them were correct.
Are you intending to track by entering the number of miles driven on each tank? It appears that way yet you have the car set to Odometer tracking.
Your two other cars are set to Trip Miles tracking so I assume this is the issue. Edit your vehicle and set the tracking to Trip Miles. Then edit your fuelups to have the correct miles tracked per trip if they aren't correct.