Powertrain - definition

Glossary

A car's powertrain includes its motor(s) as well as its drivetrain, which is the group of components that deliver power to the drive wheels.

In EVs, powertrains can consist of one or multiple motors - usually one or two. If a car has one single motor, then it's either driving the rear wheels or the front wheels. You'll see the "RWD" designation in our specs if we're dealing with a single-motor EV where the motor drives the rear wheels. In a similar vein, "FWD" denotes a single-motor EV where the motor drives the front wheels, while "AWD" implies there is at least one motor driving the front wheels and one motor driving the rear wheels (more complicated arrangements are possible, one motor per wheel, for example).

The maximum power output of the car is expressed in kW and hp. The kilowatt (kW) is equal to one thousand watts. This unit is typically used to express the output power of engines and the power of electric motors. One kilowatt is approximately equal to 1.34 horsepower.

Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are the mechanical horsepower (or imperial horsepower), which is about 745.7 watts and the metric horsepower, which is approximately 735.5 watts.

The term was adopted in the late 18th century by Scottish engineer James Watt to compare the output of steam engines with the power of draft horses. It was later expanded to include the output power of other types of piston engines, as well as turbines, electric motors and other machinery.

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