The 114-mpg electric car (but there's a catch)

  The US Dept of Energy lists the Nissan Leaf as having the equivalent of 114 mpg fuel economy on its fueleconomy.gov website.  For comparison, the Tesla Model S sedan gets a little bit lower fuel economy, but not much: 95 mpg in the 60 kWh battery system model.  Are these numbers for real?  Do the math: the Leaf is rated at 30 kWh of charge used for 100 miles of driving, according to USDOE.  That works out to 3.33 miles per kWh.  A gallon of gasoline has 115,400 Btu of energy content and a kWh has an equivalent of 3,412 Btu, so dividing the former by the latter gives a value of 34 kWh per gallon.  Multiply this by 3.33 mi/kWh and you have approximately 114 miles per gallon equivalent.
   So what's the catch?  Well, if a Nissan Leaf is a 114 mile per gallon car, then it has the equivalent of a 1-gallon gas tank.  On a good day.  The same USDOE webpage puts its range at 80 miles per charge that you could get consistently, so you'd need favorable conditions to go as far as 114 miles, the equivalent of one gallon of energy content.  Again, the Tesla does a little better (equivalent of 2 or 3 gallon gas tank), but that is because to own one you have shelled out serious money for a very high-capacity battery system.
   Now if only someone could figure out how to build an EV with 114 mpg AND the equivalent of a 10-gallon tank...don't hold your breath..../