What is a powertrain?

The powertrain combines various components, including the engine, transmission, driveshaft, axles, and differential, that collaborate to transmit energy from the engine to the wheels, allowing the vehicle to be set in motion. Defining the components:

Engine: The North American truck and bus market uses various engine types, including diesel, gasoline, alternative fuel, hybrid, and electric.

• The diesel engine (also known as a compression-ignition or CI engine) is an internal combustion engine (ICE) in which the fuel is ignited by the high temperature achieved when greatly compressed (adiabatic compression)

• The gasoline (petrol) engine is an ICE with pistons driven by explosions of a mixture of air and vapor of gasoline or other volatile fuel ignited by an electric spark.

• An alternative fuel engine is an ICE that uses fuel other than the traditional petroleum field (gasoline or diesel). For his report, alternative fuels include compressed natural gas (CNG), liquid natural gas (LNG), propane (LPG), and biofuels.

• Hybrid power utilizes more than one form of onboard energy to achieve propulsion. That means a hybrid will have a traditional ICE and one or more electric motors with battery packs.

• Electric power uses one or more electric motors or traction motors for propulsion. An electric vehicle may be powered through a collector system by electricity from off-vehicle sources or self-contained with a battery.

There is a difference between heavy (Class 8) and medium (Classes 5-7) duty trucks and heavy, medium, and light duty engines.

• Heavy duty diesels (premium) are considered 10L displacement and above used in Group 2 Class 8 trucks./tractors, large buses, and motor homes.

• Medium-duty diesels (non-premium) have displacements from 7L to 9.9L and are used predominantly in Group 1 Class 8 and Class 7 trucks.

• Light duty diesels have displacements below 7L and are to be used in Classes 2 through 7 trucks (a few have even been used in Group 1 Class 8 trucks).

Transmission: A transmission is a fundamental component of a vehicle that transfers the engine's rotation into usable energy by utilizing a set of gears and clutches to regulate the power based on driving conditions. It plays a crucial role in adjusting the power from the engine and transmitting it to the wheels, ensuring that the appropriate amount of power is transferred to keep the vehicle moving smoothly.

Driveshaft: A driveshaft is a mechanical part responsible for transferring the torque generated by the transmission to the wheels, adjusting its length to accommodate movements in the suspension system, and operating at different angles. As the engine's rotational force (torque) moves through the transmission, it is transferred to the differential via the driveshaft.

Axles: Axles play a vital role in a powertrain system, as they are located between the wheels and perform two essential functions. They bear the vehicle's weight and rotate and transmit power from the engine to the wheels. Axle assemblies support the vehicle and transfer power generated by the engine to the wheels to enable the vehicle to move.

Differential: A differential is a crucial component of both front and rear axle assemblies that assists a vehicle in making turns efficiently. It receives torque from the driveshaft and distributes it to the wheels, allowing each wheel to rotate at different speeds, making it particularly important when taking corners. Whether part of the rear or front axle assembly, the differential lets the wheels rotate at varying speeds while maintaining traction on the road surface.