What is a Powertrain?
The powertrain of a vehicle encompasses all the components necessary to generate and transmit power from the engine to the wheels. In a motor vehicle, the powertrain comprises the main components that generate power and deliver that power to the road surface, water, or air.
What does Powertrain of a Vehicle includes?
Powertrain of a vehicle includes the engine itself, the transmission, driveshaft, axles, and differential and the final drive (drive wheels, continuous track as in military tanks or caterpillar tractors, propeller, etc.).
In a wider sense, the powertrain includes all of the components used to transform stored (chemical, solar, nuclear, kinetic, potential, etc.) energy into kinetic energy for propulsion purposes.
What is the Role of Powertrain in a Vehicle?
The powertrain of a vehicle is responsible for ensuring that the vehicle can move by converting the engine’s power into motion. Without a functional powertrain, a vehicle would not be able to operate.
What is the Impact of Powertrain in a Vehicle Performance?
The performance of a vehicle heavily relies on the efficiency and condition of its powertrain. A well-maintained powertrain ensures smooth operation, enhanced acceleration, and effective handling, contributing significantly to the overall driving experience.
Different types of powertrain configurations, such as front-wheel drive (FWD) and rear-wheel drive (RWD), impact the vehicle’s performance in various conditions.
For instance, FWD systems are typically found in sedans and small cars, providing sufficient traction for everyday driving, while RWD systems are common in sports cars, offering better handling at high speeds but less traction under poor road conditions.
Additionally, all-wheel drive (AWD) and four-wheel drive (4WD) systems provide superior traction and handling in diverse weather and terrain, making them ideal for safety-focused and off-road vehicles respectively.
What are the various types of Powertrain?
1 . Internal Combustion Engine (ICE) – Gasoline
In a conventional internal combustion engine (ICE), the powertrain converts the stored gasoline energy to kinetic energy in the engine and transfers it via the transmission, driveshaft and differential as torque to the wheels of the vehicle, propelling it forward.
These engines operate by burning gasoline to generate power, but they are known for high emissions and lower efficiency, utilizing only about 20% of the fuel’s energy for vehicle propulsion. The rest is lost to heat and other inefficiencies. However, Internal Combustion Engine vehicles powered by gasoline are prevalent due to their established technology and widespread fuel availability.
2 . Internal Combustion Engine (ICE) – Diesel
Diesel engines, similar to their gasoline counterparts, burn fuel to produce mechanical power, but they are generally more efficient, achieving better fuel economy due to higher energy content in diesel fuel. However, they face challenges such as higher emissions of particulates and NOx, which have environmental and health impacts.
3 . Hybrid Electric Vehicles (HEVs)
Hybrid Electric Vehicles combine a gasoline engine with an electric motor, allowing them to reduce fuel consumption and emissions. The electric motor can power the vehicle alone at low speeds or assist the engine during acceleration, improving efficiency. Regenerative braking in HEVs captures kinetic energy to recharge the battery, enhancing overall fuel economy.
4 . Plug-in Hybrid Electric Vehicles (PHEVs)
Plug-in Hybrid Electric Vehicles function similarly to HEVs but with larger batteries that can be recharged through an external electric source. This allows them to drive significant distances on electricity alone, reducing reliance on gasoline and cutting emissions further. Once the battery is depleted, they operate like traditional hybrids.
5 . Battery Electric Vehicles (BEVs)
Battery Electric Vehicles are powered entirely by electricity stored in onboard batteries, which are recharged via external power sources. BEVs produce zero tailpipe emissions and offer high energy efficiency. Advances in battery technology continue to improve their range and decrease charging times, making them increasingly viable for more drivers.
6 . Fuel Cell Electric Vehicles (FCEVs)
Fuel Cell Electric Vehicles generate electricity through a chemical reaction between hydrogen and oxygen, with water vapor as the only emission. FCEVs combine the quick refueling capabilities of conventional cars with the environmental benefits of EVs. However, the production and storage of hydrogen and the infrastructure for fueling stations remain challenges for widespread adoption.
Must read: Fuel Cells – Uses, Benefits and Working
What are Alternative Powertrains?
Alternative powertrains include propulsion systems that are not based exclusively on the popular internal combustion engine. This may include hybrids, full battery electrics, hydrogen fuel cells, compressed air, and many other types.
Presently, vehicles with internal combustion engines are by far the most popular choice of powertrain. These can either be spark ignition (SI) in the case of gasoline or compression ignition (CI) for diesel. However, concern for the environment has led to policy targets on carbon emissions globally. In transport, this is being achieved by encouraging greater emphasis on increasing the efficiency of existing means, while promoting reduced-carbon alternatives.
Electrification of road vehicles has significantly increased the production of both hybrid engines, which use a mix of ICE and electrified powertrains, and fully electrified systems. The energy for electrified systems can come from a range of sources, including onboard generation, plug-in charging or even hydrogen fuel cells.
Different types and configurations of alternative powertrain systems have evolved as part of the electrification trend. Hybrid powertrain systems combine both conventional ICE engines together with some electrified support:
• Micro hybrid – has a low voltage operation to support stop/start functionality.
• Mild hybrid – the electric motor provides a boost to the combustion engine.
• Full hybrid – has both ICE and electrified drives, but the vehicle can be propelled independently by the electric motor. The energy for the motor is stored in onboard batteries and can be charged by the combustion engine or optionally plugged into an external charger. These hybrid systems require hardware and control systems for both the electrified and conventionally powered powertrain.
• Fully electric vehicle (EV) – typically simpler from the hardware perspective and only needs a single control system, but usually has no onboard way to recharge. They therefore need larger batteries for practical range and have dependence on external recharging sources.
Electric Vehicle Powertrain Design:
With the right framework conditions, alternative fuels have the potential to play a key role in improving air quality and reducing CO2 emissions. The automobile industry has put forward a number of solutions through its investments in cleaner technologies. These will bear fruit only if there is full cooperation between utility providers, infrastructure companies, the energy sector, standardisation bodies and the automotive industry – with the full support of governments.
PRACTICE QUESTIONS
QUES . Consider the following types of vehicles: UPSC PRELIMS 2025
I. Full battery electric vehicles
II. Hydrogen fuel cell vehicles
III. Fuel cell-electric hybrid vehicles
How many of the above are considered as alternative powertrain vehicles?
(a) Only one
(b) Only two
(c) All the three
(d) None
Answer – (c)
