What Is a Powertrain?

A powertrain is an assembly of every component that pushes your vehicle forward. Your car's powertrain creates power from the engine and delivers it to the wheels on the ground. The key components of a powertrain include an engine, transmission, driveshaft, axles, and differential. Let's break down each one by one:

Engine: As the heart of your vehicle, an engine generates power to drive the car. An engine consists of pistons that move up and down inside cylinders and a crankshaft that translates the reciprocating motion into a rotating motion.

Transmission: A transmission is a basic component in your car that makes sure the proper amount of power is transmitted to the wheels. Like a car's gearbox, the transmission takes the power from the engine and adjusts it according to driving conditions, ultimately transferring it to the wheels.

Driveshaft: A driveshaft is a component that transfers the torque from the transmission to the wheels. To perform this task, it has to work through various angles and change its length to adjust to movement in the suspension.

Axles: Axles are an important member of a powertrain. It lies between the wheels and mainly performs two functions: first, it puts up with the weight of the vehicle and it also rotates and transmits the power of the engine to the wheels.

Differential: A differential is a part of the rear axle. It allows each rear wheel to turn at a different speed. For instance, the differential is important when turning a corner, as the outside wheel needs to rotate faster than the inside wheel.

The powertrain is crucial because without the system working properly, your vehicle cannot move forward. To sum up, it's a group of parts that generate, convert, and consume energy to thrust your vehicle into motion.

When people talk about a high-performance sports sedan, we often hear how the vehicle is capable of smooth steering, acceleration, and brakes, as well as excellent body control and enhanced safe driving. Well, these techniques are important but not the 'be-all-and-end-all' of a successful sports car. Its staggering performance numbers such as hundreds of horsepower or reaching 0-100km/h in seconds come from your powertrain, and nowhere else. As a source of power generation, a good quality powertrain is a key to a better operating range, acceleration, and top speed. So, next time you accelerate your car from a standstill and feel a push of your engine power, just know that your powertrain propelled your vehicle. 

These days, the importance of the Powertrain Control Module (PCM) has been recognized for its role in improving fuel economy and responding to global environmental regulations by controlling exhaust emissions. The PCM is the electronic control system that controls what your engine and transmission do. Thus, it is like the main computer of your car that controls fuel delivery, emissions functions, and many others. It also affects your engine's performance and drivability significantly. 

A powertrain warranty is a warranty that covers the powertrain parts in case they are impaired for a set period. So, while you are covered, the automaker will pay to have your damaged parts replaced or fixed.

A powertrain warranty is typically different from a base car warranty in what they cover and don't cover. The powertrain covers the cost of fixing or replacing components of the powertrain. While the base can protect a much broader range of parts of your car, and the powertrain warranty usually comes in after the base coverage.

For example, a base warranty covers CV boots. On the other hand, a powertrain warranty covers CV joints which are an actual mechanical component but may not cover the CV boot which is a flexible rubber part that protects the CV joints. Thus, a powertrain warranty can be seen as coverage that covers more important and expensive mechanical components inside your engine, transmission, and differential.

The words “powertrain” and “drivetrain” are often used interchangeably, but they are a little bit different. Simply put, a drivetrain transmits power to the wheels. A powertrain consists of an engine (or a motor) and a drivetrain. The drivetrain, like the powertrain, is not a single component of your vehicle. The drivetrain is made of the transmission, driveshaft, axles, differential, and wheels.