Being bored at work (need another coffe to start working). I was looking at good environmental cars at epa when I to my suprise found that the stick shift insight scores very low on the "air pollution" score... see this link . How come?

I must confess I was suprised by this as I assumed the insight was the greenest car around, and it is as long as you pick the automatic.... something just doesn't seem right.... the automatic is the greenest car and the stick shift is quite a pollutant? How come the automatic is that good?