Electric engines can be more than 90% efficient and even up to 98% efficient while combustion engines are 30 to 45%. However, this does not take into consideration the electric power transmission loss, which is between 8 and 15%. Then there is the electric generation which has different efficiencies depending on the mode of transmission. A coal fired plant will be about 33% to 40% efficient. Adding the power loss, and you have about the same efficiency as a gas powered engine. These calculation are something I could not do but there are those who do and it is a wonder why the information is not being used to shows how overrated electric cars are.