The G450 shares the wing of the G-IV, but has the same forward nose section as the G-V/500/550, with extra lenghth observed between the main door and the side cockpit window.
The G-IV engine is not the same as the G450s hence another difference: the G-IV engine looks like the Fokker 100's (same TAY models, silver exhausts), the G450's is the same as the G-V/500/550 (full cowling of the engine).
The G450 is fitted with EVS/Kollsmann window below the nose, like the G500 and G550. However some G-IVs are now equipped as well.
The G-V is similar to the G500/550 but is not fitted with standard EVS, and has 6 windows (7 windows for the G500/550 but careful! I have heard that 3 G-Vs have 7 windows on the right side. Maybe some late models?).
The G500 is the same as the G550 (lower MTOW and fuel capacity).
The G400 is the same as the G-IV, except that it has the EVS as standard equipment.
The G300 is the same as the G400, but with less fuel capacity and lower MTOW, but with better payload and T/O performance.
G-IV
G400
G450
G-V
G500
G550
