The reason electric motors can be faster off the line and at lower speeds is the torque. While, as mentioned in earlier replies, the torque of an electric motor is instant, just as importantly it is constant. ICE's have to run through their gears, and the torque varies in each gear as speed...
My dealer gave me a print out when I went in to reserve a 2013 SL to lease. It listed the date of manufacture as Feb. 8, and an estimated delivery date (to Honolulu) of Mar. 15.