The A320 family don't care where you load them for Specific Air Range (SAR) considerations.
Originally Posted by Getting to grips with fuel economy, page 10, para 3
The A320 family does not show the same SR variation with CG as the other aircraft. The aft CG produces worst SR at FL290, crossing over to show an improvement at higher flight levels. The SAR variation is much smaller also. This is due to a complex interaction of several aerodynamic effects. The SAR can be considered effectively constant with CG position. Loading is therefore not critical for fuel economy for the A320 family.
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