Growing crops to make ethanol is not particulatly green. In fact, in most existing production loops we would be better off environmentally to just burn pure gasoline than produce the ethanol to mix into it, unfortunately. Too much water, too many tractors and trucks, and way too much electricity into ethanol production to be worth what we get out of it. And the bit of carbon the crops sequester doesn’t overcome it. Electric vehicles are by far the greenest option right now.