If you consider yourself a car enthusiast, you should be familiar with every component of not only your automobile, but also most of the cars you are familiar with. It’s not about being a nerd or a geek; it’s about being aware. One such thing, and one that is very popular these days, is a car’s Powertrain. When it comes to drivetrains, it’s conceivable that most of us are familiar with the drivetrains used in automobiles today, if not the types themselves.
We bring you a battle of Drivetrains! RWD vs FWD vs AWD vs 4WD
But what precisely do they do? What’s the distinction? Which of these is superior? Read on to find the answers to questions that may have arisen in your mind.
What exactly is a car’s drivetrain?
A drivetrain is a mechanism that links the gearbox of an automobile to the axles on which the car travels. In amateur terms, a drivetrain is the set of components that transmits power from the engine to the wheels, allowing the vehicle to move.
A drivetrain, which comprises components such as a driveshaft, axle shafts, U joints, CV joints, and so on, assists a vehicle for delivering power to the wheels.
Drivetrain Varieties
Most automobiles in the early days of motoring were rear-wheel driven, which meant that the power from the transmission flowed directly to the rear tyres. However, as the automotive industry matured and firms engaged in R&D, the drivetrain game shifted and new drivetrains emerged.
Rear Wheel Drive (RWD)
A rear-wheel drive vehicle is one that distributes power solely to its back wheels. The amount of power delivered to the rear axles determines how well a RWD vehicle performs.
RWD vehicles were popular in the 1980s and 1990s. RWD automobiles have long had a particular place in the hearts of automotive fans due to their ability to move the rear end out. RWD vehicles have greater balance since their weight is distributed more equally across the vehicle. RWD automobiles manage higher horsepower and vehicle weight, which is why this technology is typically employed in sports sedans, police enforcement vehicles, race cars, and so on.
However, because of the driveshaft, the automobiles have less interior room and may not have a good grip on wet roads.
Front Wheel Drive (FWD)
Car manufacturers began experimenting with front-wheel drive cars in 1895. The term FWD refers to the power being transferred to the vehicle’s front wheels.
FWD technology rose to prominence in the 1970s, when manufacturers such as Audi and Saab used it. Most automobiles in India and throughout the world use a FWD Powertrain.
The front-wheel-drive system is reported to be more efficient because of its less weight, which results in fewer carbon dioxide emissions, improved fuel efficiency, good grip on a slick section of road, and a larger interior for the passengers.
4 Wheel Drive (4WD)
This is the preferred option for most off-road vehicles. The four-wheel-drive option provides power to all four wheels of a vehicle, providing significantly more power and traction.
4WD cars are typically fitted with a transfer case, which allows the vehicle to switch to RWD transmission to conserve gasoline and return to 4WD mode as needed. The number 44 denotes the number of wheels and the number of wheels driven by the gearbox.
Part-time 4WD systems are also available. In typical driving circumstances, they allow you to run your car in two-wheel drive (2WD) mode. Most systems include low and high ranges as well. Low gives greatest traction in off-road circumstances, while high is for slick on-road conditions such as snow, ice, loose sand, or gravel.
In India, the most popular 4×4 vehicles are the Maruti Gypsy and the Mahindra Thar, which are noted for their toughness and adaptability. A 4WD car may have less traction than its AWD rivals because of its RWD maturity.
All Wheel Drive (AWD)
The common assumption is that AWD and 4WD are synonymous. While all have all four wheels turning and operate on the same principles, there are some major distinctions that distinguish the two kinds.
Part-time AWD is also available. This system distributes torque to either the front or rear wheels, while the other wheels engage automatically when road conditions cause more traction. AWD improves traction in snowy situations and on mild off-road terrain. It can assist you in navigating mud, sand, and other loose surfaces.
While most of the 44 transmit power to the rear wheels when necessary, the AWD cars are mainly FWD or RWD depending on the scenario.
Most AWD vehicles these days are equipped with an engine control unit (ECU) that determines the amount of power and traction that a wheel receives, as opposed to a 4WD vehicle, which delivers an equal amount of power to all wheels regardless of the condition in which the car is in.
Also Read All about CVT vs DCT vs AMT
AWD vs FWD vs 4WD vs RWD
Fuel Efficiency
Rotational energy is produced by engines. The less efficient the system is, the further that energy must go and the more times it must change directions before turning the wheels. So, theoretically, the most efficient drivetrain is a transverse (perpendicular to the direction of movement) engine situated immediately next to the axle its powers. This means that a front-engine FWD or rear-engine RWD configuration is the most efficient.
Shafts that connect the engine to an axle at the opposite end of the automobile add inefficient mass and rotational inertia, and the bevel or worm-type gears necessary to redirect that rotational energy 90 degrees contribute further inefficiencies. With a classic internal combustion engine, AWD will never be as efficient as FWD or RWD. AWD systems with an electric motor at either axle, such as in the electric Tesla Model Y or the plug-in hybrid Toyota RAV4 Prime, are notable outliers.
Space Efficiency
Again, a transverse engine snuggling up against the driving axle saves the greatest space. Sir Alec Issigonis showed this argument with the original (front-engine/FWD) Mini, while vehicles such as today’s Smart ForTwo and Renault Twingo provide a counterpoint for a rear-engine/RWD configuration. Because there are no shafts, transmissions, or other pieces encroaching on the cabin, such vehicles’ flooring may be flat, and most of the vehicle’s length can be devoted to carrying passengers and things.
Best Traction?
The overall coefficient of friction between the driven tire(s) and the road surface is multiplied by the instantaneous mass pushing down on these driven tyres to calculate a vehicle’s potential accelerative traction. Because driving all four wheels is the only method to make 100 percent of the vehicle’s weight work for this equation, AWD has an inherent advantage in accelerative traction.
Cantilevering the engine off the front of a FWD axle or the back of a RWD axle is analogous to placing a huge kid on a teeter-totter—it adds weight to the driven axle while subtracting weight from the undriven one. This is beneficial for traction when starting off on a straight path. It’s less suitable for dynamic handling, as the weight imbalance can cause under-steer or over-steer when turning aggressively in low traction circumstances.
We need also keep in mind that most of a vehicle’s weight is higher than the axles, so when we speed ahead, the centre-of-mass shifts backward, temporarily increasing the pressure on the rear axle. As a result, placing the engine near or towards the rear of the vehicle enhances the traction available to a RWD vehicle.
Safest?
To be honest, the driving axle (s) has nothing to do with passive safety, however in slick situations, breaking traction with FWD results in under-steer, whilst breaking traction with RWD might cause over-steer. Under-steer is often regarded “safer” or at least more benign than over-steer because you’d slide forward toward travel rather than laterally or perhaps backwards as with over-steer. Depending on its design, an AWD system might lose traction at either axle.
Although placing the engine forward of the occupants in the crumple zone might provide some extra protection, current mid- and rear-engine vehicles are just as crash worthy as front-engine vehicles because of clever engineering and materials science.
A neutral weight balance and a low polar moment of inertia are vital for improving the driver’s capacity to actively prevent an accident by driving out of a risky position, hence a mid-engine RWD or AWD vehicle might be argued to be “safest.”
Handling?
We can suggest vehicles with each of the aforementioned drivetrains, but the engineering and driving-fun decks are stacked against FWD. Because each tyre only has so much friction force to distribute, every amount of longitudinal acceleration force generated comes at the sacrifice of force that may be delivered laterally for turning. That implies that powering out of a turn in a FWD car is significantly less rewarding. As a result, the decks are naturally stacked in favour of RWD and AWD cars that lean greater torque to the rear.
Of course, as overall engine power and torque approaches the point where two tyres are threatened, AWD becomes required to safely or more cleanly let power down while exiting corners.
Acceleration?
Only AWD cars can fully use every ounce of onboard mass to create accelerative friction. However, keep in mind that mass, friction, and rotational inertia are all natural opponents of acceleration, and AWD systems have a lot of all three. As with the winter traction example above, it’s likely that—at least four cars with less than 400-500 horsepower—fitting a pair of drag slicks or dry traction-optimized summer tyres to a RWD vehicle will allow it to easily out-drag a comparable AWD vehicle on all-season tyres.
Also Read, SUV vs Sedan
Which drivetrain is better for India?
The car’s drivetrain is important. You should choose a vehicle that best meets your requirements. RWD is the car to choose if you are an automobile enthusiast who enjoys driving. Our country’s RWD vehicles include the Mahindra Scorpio, XUV 500, Ford Endeavour, and Toyota Fortuner.
Front wheel drive automobiles are a good option if you require a vehicle that is affordable and does the job.
Most automobiles in India are front-wheel drive and popular among the populace because of their inexpensive cost, ease of maintenance, and improved fuel efficiency.
However, if you’re torn between a 4WD and an AWD car, you might not have much of a choice. Most automobiles in the nation are marketed as 4×4. Choose a vehicle that can fulfil multiple functions, such as a tough off-roader and a flexible and energetic car that can cruise comfortably on the highway.
Why are front-wheel-drive automobiles so popular in India?
As seen, most automobiles in India have front-wheel drive. So, what is the reason for this? Let us investigate.
A front-wheel-drive car has a smaller turning radius than a rear-wheel-drive vehicle or an AWD vehicle.
In a front-wheeled vehicle, the propeller shafts carry power over a greater distance, resulting in more power loss.
The more the power loss, the better the fuel economy, mileage, and acceleration
Because of smaller and lighter components, there is more space within the car, and a large cabin attracts more customers.
