Gasoline differs. Specifically, the regional gasoline blends differ, and incompatibly. Some papers on this topic: http://www.hks.harvard.edu/fs/emuehle/Resea

Gasoline differs. Specifically, the regional gasoline blends differ, and incompatibly. Some papers on this topic: http://www.hks.harvard.edu/fs/emuehle/Research%20WP/Gasoline%20Content%20Regulations%202_05.pdf http://www.hks.harvard.edu/fs/emuehle/Research%20WP/Gasoline... http://cbey.research.yale.edu/uploads/File/muehlegger_23.pdf http://cbey.research.yale.edu/uploads/File/muehlegger_23.pdf