If it’s your first car you’re buying, you may not care so much about the type of drivetrain system you’re getting. That shouldn’t be the case, you know.
The drivetrain system determines how a car acts on varied road conditions, and it is crucial in your car's handling and performance. In short, you need to include it in the equation.
Drivetrain types can get a little bit complicated, but don’t worry—I’ll explain them in detail below.
What Are the Four Types of Drivetrain Systems?
The Drivetrain
First, let’s talk about what a drivetrain is. A vehicle’s drivetrain refers to the set of components involved in conveying power to the driving wheels but excludes the part that generates that power. In other words, the engine or motor is not counted as part of a car’s drivetrain.
4 Drivetrain Types
- Front-wheel drive (FWD)
- Rear-wheel drive (RWD)
- Four-wheel drive (4WD)
- All-wheel drive (AWD)
Let’s talk about each type and understand not only how they work but also how they vary from one another.
Front-Wheel Drive or FWD
FWD is the most prevalent drivetrain system in the automotive market. With front-wheel drive, the engine sends power to the front wheels. The rear wheels don't receive power, so we say that it’s the front wheels 'PULLING' the car.
A driveshaft is not necessary for a FWD car since the driveline does not deliver power to the rear wheels. The engine and transmission are set either transversely or in line with the chassis. For transverse, the rotation axes of the motor and wheels are parallel.
The transmission conveys power to the front axle, which then directs this power to the front wheels. If the front wheels of the car don't get traction, the vehicle can't move.
Pros and Cons of FWD
Pros
- The FWD drivetrain allows for more cabin and trunk space.
- With the weight of the engine bearing down on the driving wheels, FWD vehicles have better traction in snowy and slippery conditions.
- FWD offers better fuel economy.
- An FWD car has low maintenance cost due to less moving drivetrain components.
Cons
- Heavy wear on the front wheels since they handle all the work, including acceleration and turning.
- Uneven weight distribution affects cornering performance.
Rear-Wheel Drive
If you haven’t guessed it yet, RWD means the transmission system delivers power from the engine to the rear axle of the vehicle. So, we say that the rear wheels are 'PUSHING' the car forward. The front wheels don't receive power, and their only function is for steering.
Most manufacturers are gradually phasing out RWD cars since they view front-wheel drive as the more practical and cost-effective configuration.
Pros and Cons of RWD
Pros
- This system is suited for performance cars because it can handle high engine power and torque.
- The even distribution of weight results to better balance in RWD vehicles.
- The agility associated with RWD systems makes it easy to manoeuvre the car and avoid obstacles.
- The wheels share in the work: the rear wheels do the driving, while the front wheels do the steering.
Cons
- RWD vehicles have poor performance in slippery conditions as they are prone to loss of traction.
- Maintenance cost is high due to an increased number of moving drivetrain components.
All-Wheel Drive
An AWD system delivers power to all the four wheels of the vehicle all the time. It makes use of centre, front and rear differential. The centre differential distributes power evenly between the front and rear axles.
However, in some AWD cars, the distribution of power is not equal. The system delivers power to two driven wheels under normal road conditions and automatically activates the AWD when road situations demand more traction or threaten stability.
A more significant portion of power can be distributed to the front while the rear receives a smaller percentage. Power distribution depends on the type of terrain that the vehicle negotiates and which wheels experience slip.
An AWD system is controlled by either a hydraulic or electronic system. AWD cars are suited to slippery conditions at the cost of more fuel. It is often confused with the four-wheel-drive because both can power all four wheels of the car.
Pros and Cons of All-Wheel Drive
Pros
- It’s ideal in most terrains and road conditions.
- AWD cars have better handling characteristics.
Cons
- All-Wheel Drive vehicles consume more fuel
- Maintenance cost is relatively high due to the increased number of moving drivetrain components
Four-Wheel Drive
For the 4WD system, power is delivered to all four wheels when 4×4 is engaged. The lines differentiating 4WD vs AWD can get blurry at times. However, there is a difference in these drivetrain systems.
4WD Vs AWD
The differentials in 4WD cars are located both at the front and the rear part of the vehicle, and there is a transfer case that allows selecting the mode for controlling the vehicle. With 4WD, you can choose to operate the vehicle in RWD or 4WD when full traction is required.
Although the 4WD system is akin to the AWD system, the 4WD is designed to be more rugged.
Types of 4WD
There are two 4WD types: part-time and fulltime.
Part-time Vs Fulltime 4WD
In a part-time 4WD, aka on-demand 4WD, the driver decides which drive mode to use in a particular situation. As designed, its default setting is the 2WD mode for dry pavement. The driver engages all four wheels if he needs more traction and as he sees fit.
In fulltime 4WDs, aka permanent 4WD, the vehicle shifts to the best drive mode that the terrain demands without input from the driver.
A part-time 4WD drives the four wheels by locking both axles using a shift lever. It includes a Hi and Lo speed range. A fulltime 4WD drives all four wheels at all times.
Pros and Cons of 4WD
Pros
- It offers versatility which makes it suitable for various terrains and weather conditions.
- The 4WD system provides a lot of traction which comes handy in challenging road conditions such as muddy terrains.
Cons
- The 4WD drivetrain system operates in RWD most times which provides less traction.
- It has more drivetrain parts that move hence increased maintenance cost.
Which Is the Best Drivetrain?
The question 'which drivetrain is the best?' has no cut-and-dried answer. The choice on which drivetrain to go with depends on an individual’s needs. The general truth is that each of these drivetrain systems is suited to different conditions.
RWD Vs FWD
If you’re after fuel efficiency, front-wheel drive is ideal for you. On the other hand, if you want to get the driving experience and live in an environment with paved roads and dry weather, rear-wheel drive would be perfect for you.
If you live in an environment that has slippery and snowy road conditions during some times of the year, all-wheel drive and four-wheel drive are suitable.
Sam O.