According to the 6th paragraph in the text (lines 43-52), one of the Corporate Average Fuel Economy goals for the fleet in the United States is average 54.5 miles per gallon
The modal verb may in the fragment of the text “It may be years before the economic benefits of natural gas vehicles can be realized” (lines 35-36) is associated with the idea of
The sentence of the text “But were production to increase significantly, economies of scale would bring prices down” (lines 28-29) has the same meaning as: