The "electric vs gas car" debate is a popular one, and of course the comparison depends on the metric, electrics more efficient for stop 'n go/about 60% of fuel cost/about 50% "cleaner". I owned an electric car in the late 80s, and the Electric Auto Association I belonged to figured our battery cars were about the equivalent of a 80 mpg gas car (all considered).

The term "energy density per volume" comes into play here (diesel fuel about 15x more, pressurized hydrogen 2x more than lithium battery). Still, electric cars don't have big engines or pressure tanks (and are lighter). For energy density reasons, batteries thought to be future domain of small car, hydrogen domain of large truck or plane (where wt of large tank is less critical) which requires longer range. Better battery tech may change this someday.