You may have at some point in your dealings with cars heard terms like horsepower, Newton metres, automatic gearboxes and all-wheel-drive? Such terms are only related to a vehicle's powertrain. There is also another closely related term called "drivetrain".
Although the drivetrain is still a part of the powertrain, this article by Naijauto.com will discuss how they are related and the difference between a drivetrain and powertrain.
1. What is a drivetrain?
The drivetrain of a car refers to all components of the car (minus engine or motor) that work together to deliver power needed to drive the car wheels.
The drivetrain design varies in types of vehicles, consisting of different components. For example, in manual transmission cars, a drivetrain is often formed of flywheel, clutch, gearbox, propeller shaft and rear axle while in their automatic counterparts, there are torque converter, transmission together with propeller shaft and rear axle as well.
The power train is considered to be the engine or motor and the drivetrain
2. What is a powertrain?
On the other hand, the powertrain refers to every component of the car that is involved in converting the engine power into actual movement of the car. Basically, the power train is considered to be the engine or motor and the drivetrain. The powertrain comprises the engine, transmission, drivetrain, differentials and finally the drive.
The drivetrains of Front-Wheel-Drives, Rear-Wheel-Drives or All-Wheel-Drives are usually different owing to the way the engine power is sent to the wheels.
Look familiar? This is the so-called car powertrain
3. Parts of the Powertrain & their functions
As mentioned earlier, the difference between a drivetrain and powertrain lies in their component parts. The powertrain consists of the engine or motor and all parts that make up the drivetrain while the drivetrain consists of all the parts of the powertrain minus the engine or motor.
The key parts of a powertrain consists of:
- Axles and Wheels
The engine is the heartbeat of the powertrain. It is in the engine that fuel and air burn causing the piston to move up and down. This piston movement consequently causes the crankshaft of the engine to rotate.
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In a car powertrain, it is the transmission that converts the rotation of the engine into usable energy. In manual cars, the transmission is made up of of the gearbox and clutch, both of which work together to transmit and convert the engine's power into actual rotation of the wheels. What happens in reality is that the clutch in manual cars connects to or disconnects from the engine power when the gears are shifted either higher or lower or put in neutral.
For automatic cars, the transmission makes use of electronically controlled gears without needing manual selection. A device known as the torque converter performs the same function as the clutch in automatic cars.
Location of powertrain components inside a rear-wheel-drive system
The driveshaft which is also known as the propeller shaft is a long rotating shaft that runs the length of the vehicle, down to the middle. This shaft serves as a bridge for the power coming from the engine/transmission to the wheels.
Most front-wheel drives don't need a driveshaft; they are equipped with a transaxle - a compact unit comprising the transmission and differential.
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It is the differentials that make it possible for the wheels in a moving car to spin at different speeds. Without a differential, all the wheels of a car would be connected together and move at the same speed.
While this is not particularly a problem for a car moving on a straight road, it spells potential disaster for a car trying to make a turn. Without differentials, taking a swift turn can topple a car.
Illustration of differentials' function inside car
3.5. Axles and wheels
For you to have rotating wheel, there must be an axle. The axle is a shaft upon which the wheel rotates.
Finally, the wheels themselves also make up the drivetrain and consequently the powertrain.
Now that you know the relationship and difference between a drivetrain and powertrain, it is worth mentioning that the powertrain of hybrid cars is considered to include the batteries, electric motors and control algorithms.
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