You don't defeat a stupid argument with more of the same. Air resistance, which is the main variable in mileage at higher speeds, increases exponentially with speed. Double your speed and you quadruple air resistance. What the article says is factually correct. The way to argue against it is to point out that we are free people accustomed to a certain lifestyle and have priorities other than trying to knock ten percent off our gas bill.
"Double your speed and you quadruple air resistance."
I don't plan on running 110 MPH.