Edit this Published in Freakonomics Radio The Downside of More Miles Per Gallon Listen 6 min Queue Download this audio Want to embed this player? Use the code below. More info. <iframe frameborder="0" scrolling="no" height="130" width="100%" src="https://www.wnyc.org/widgets/ondemand_player/wnyc/#file=/audio/json/270828/&share=1"></iframe> Share on Facebook Share on Twitter Email a Friend The gas tax doesn't work well, and it's only going to get worse. What's next?