Torque - definition

Torque is a physical quantity that indicates the traction in an engine design. The physical unit for torque is the newton-meter (Nm). While horsepower provides a measurement of a motor's overall performance, torque provides a simple measurement of the maximum twisting force that it can generate, when worked hard. To put it another way - horsepower conveys the motor's overall capability across all conditions. Conversely, torque output conveys the peak output available from that motor, in a specific moment when it's doing its hardest work.

Unlike internal combustion engines, EVs have the added bonus of being able to deliver full torque with no delay whatsoever. That's why an EV's acceleration feels so memorable - all of the torque is available right then and there, instantly.

Maximum torque is actually reached at a low rpm in an electric motor, and it stays close to constant right up until you reach maximum engine power. From there, the torque drops and the engine power remains constant. As soon as the point of maximum torque is reached, the vehicle no longer accelerates faster.

Related terms:

• Acceleration
• Powertrain