Let’s look at the efficiency of electric cars and compare them with gasoline-powered vehicles. Are EVs as efficient as they are claimed to be?
When talking about electric cars, first of all, one of their main advantages is energy efficiency, which saves money. Traditionally an EV is considered to be a good purchase in terms of lower running costs. Autocar has studied the topic and shared it with readers.
Electric vs gasoline/petrol
Electric powertrains surpass conventional internal-combustion engines by efficiency. Even a very good gasoline engine converts only around 40 percent of energy in the fuel into work, while 60 percent of the heat converted from gasoline is wasted.
Electric motors, in contrast to gasoline engines, convert more than 90 percent of electricity into useful work. So, they are obviously more economical, especially given the fact an electric motor can recover some energy by generating electricity when the vehicle slows down.
According to a GGE formula (‘gasoline gallon equivalent’), one Imperial gallon of gasoline equates to about 40 kWh of electricity. The fuel consumption of a car with a 1.5-liter gasoline engine is approximately 55 miles per gallon, so, 1.6 gallons should be enough to cover the distance of 88 miles.
An electric car of a similar size with a 64-kWh battery pack (useable charge) consumes roughly the same amount of energy as 1.6 gallons of gasoline. So, this vehicle with this battery capacity can travel nearly 236 miles at a realistic 3.7 mi/kWh, and its energy efficiency figure is 64 kWh : 236 miles = 0.271 kWh/mile.
88 miles against 236 miles is a significant difference of 148 miles becoming possible due to the efficiency of the electric powertrain and energy recovery through regenerative braking.
What about HEVs and PHEVs?
Hybrids and plug-in hybrids are more fuel-efficient than gasoline vehicles but less efficient than pure electric cars. Automakers constantly improve the fuel economy of such vehicles in various ways: by recovering energy through regenerative braking or by running the combustion engine in more optimal operating cycles for less fuel consumption.