I think FSX has generic names for the tanks, so the tanks in the Acceleration Hornet are not properly labeled. The tanks labeled as Left, Left Aux., Right and Right Aux. are actually all located on the longitudinal axis of the aircraft, so they can have different weights (in the real Hornet they are numbered as Tanks 1,2,3,4). The Left and Right tip are internal wing tanks, and as such they have equal weights.