The G63 get from 0-60 to in 5.0 seconds and through the 1/4 mile in [email]13.5@106 . That certainly is moving for an SUV but that is similar to what the previous G55 AMG did with its supercharged M113K 5.5 liter V8. The GL63 AMG which also was tested by Car and Driver just like this 2013 G63 AMG managed a 13.2@109 with 0-60 coming in 4.8 seconds. Yes, the GL is just slightly lighter but maybe it's the ancient aerodynamics of the G63 playing a role here?
The full test numbers are below. Pay attention to the skidpad result which looks more fitting for a barge than an AMG. The G is simply showing its age but that also happens to be part of its appeal.