A Yale Climate Connections report says internal combustion engine (ICE) vehicles are “fundamentally inefficient,” primarily due to the vast amount of original energy that is wasted in gas-powered vehicles.

For every $5 gallon of gasoline, only $1 of it is used to move an ICE vehicle along the road. However, the cost of charging an EV is equivalent to $1.41 per gallon in the U.S., making it cheaper to operate than an ICE vehicle.

Gas-powered vehicles waste about 80% of the energy in their fuel. Most of the energy is consumed by the heat produced in the engine. Other energy inefficiencies stem from pumps and fans cooling the engine, mechanical friction within the transmission and drivetrain, and auxiliary electrical components such as heated seats, lights, and audio system. Only about 20% of the original energy ends up going to the wheels.

Gas-Powered Vehicle Energy Loss from 100% of Original Fuel

75-84% of original energy is lost

• 68-72% engine losses

• 4-6% parasitic losses

• 3-5% drivetrain losses

• 0-2% auxiliary electricity use

​By contrast, energy enters the EV as electricity, which powers the drivetrain. Since EVs do not need to convert one form of energy to another, it is more energy efficient than ICE vehicles. But EVs are not completely efficient, since roughly 11% of the energy is lost. Energy loss is due to the recharging of the battery, and electricity used for cooling and power steering, as well as drivetrain and auxiliary components. About 87-91% of the original energy ultimately goes to the wheels.

Electric Vehicle Energy Loss from 100% of Original Fuel

31-35% of original energy is lost, but 22% is returned through regenerative braking

• 10% charging loss

• 18% drivetrain losses

• 3% power train cooling and steering

• 0-4% auxiliary electricity use