The Nissan leaf (@99mpg equivalent) is a small car equivalent roughly in size to the Fiat Panda Eco (@56.5 mpg). The Nissan Leaf energy spec will be at the battery @ 32kwhr and doesn't take into consideration the transmission and the battery loses with respect to the generation of the source electricity (Lithium Ion has 80% efficiency so you can easily knock 20-30 mpg of that 99mpg headline figure when taking these losses into account) so the differences aren't to great when everything is taken into consideration especially when you take into account the real world combined driving figure as a combination of motorway, urban and city driving. So the reality on the number of nuclear power stations would in reality be nearer 400. The other problem is of course would be the peak loading issues for the electrical grid as everyone tops of their car batteries just before the rush hours. To take the peak loading problem into account you could easily double or triple that 400 number. The discrepancy between the first figure (2000 nukes) I ball parked is due to the fact that only 25-30% of oil consumption is actually used for vehicle transportation energy consuption requirements for the US.

The other major problem of course is replacing millions of those cheap toxic $9000 Li-ion battery packs every 3-5 years or so in the rather small and very compact Nissan Leaf.

The other major issue is the actual problem of the distribution of the required electricity, i.e. around 20 Nuclear Power stations to cater for the peak electricity loading for a city the size of Houston for its rush hour.

Its not the kind of a world I would want to live in. I'll take the horses any day.