By the looks of the Gear ratio of the second and third gears of the Auto transmision it looks like the Auto might be really quick..... they look like they might be at least as quick as the Manual if not faster
Gear ratios:
GT(Treme 3650) GT(5R55S) V-6(Tremec T5) V-6(5R55S)
I 3.38:1 3.22:1 3.35:1 3.22:1
II 2.00:1 2.29:1 1.99:1 2.29:1
III 1.32:1 1.54:1 1.33:1 1.54:1
IV 1.00:1 1.00:1 1.00:1 1.00:1
V 0.68:1 0.71:1 0.68:1 0.71:1
Final drive ratio
GT (Tremec 3650) 3.55:1
GT (5R55S) 3.31:1
V-6 (Tremec T-5) 3.31:1
V-6 (5R55S) 3.31:1