Electric cars are the most efficient cars today due to their inclusion of regenerative braking, low heat generation, and near zero energy spent when idle. 

• Regenerative Braking

  • Regenerative braking is a breakthrough that adds driving range by returning the car’s kinetic energy to its batteries.

  • In gas cars, that energy is lost to heat in the brakes.  Regenerative braking works when stopping,  the motor now putting  energy  back into the batteries, acting as an electric generator.

  • “An additional benefit is that regenerative braking keeps the electrolyte from forming layers of acidity within the battery.  This increases the efficiency and life of the battery” (Whitener 37). 

• Low Heat

  • Good efficiency is hard to achieve in an internal combustion engine car, because combustion creates heat.

  • Each energy transfer through a gear or bearing loses additional heat in the drive train, totaling eight to nine percent. 

  • “The internal combustion engine is notoriously inefficient.  [Internal combustion] engines have an efficiency of 20-25% and diesel 30-40%” (Williams). 

    • This means that over 60% of gasoline’s energy is lost to heat, without being put to use to move the car

  • Electric vehicles (EV’s) overall lose about 40% of their propulsion energy to heat, because they use a fixed gear ratio instead of a variable ratio transmission, and concentrate heat in the control electronics.  

• Energy Spent when Idle

  • While gas cars in a traffic jam or at lights burn up valuable fuel just sitting, electric cars can sit endlessly, spending virtually no energy. 

    • “In traffic, an electric vehicle, standing still or crawling, uses almost no power, whereas a New York taxicab consumes half a gallon of gasoline and adds to [the] pollution problem” (Lincoln 69).