When buying a car, new or used, the question of the type of drivetrain arises. Rear-wheel drive, front-wheel drive, four-wheel drive, which system is the most suitable for my needs? Also, with the emergence of hybrid and electric models on the market, new variants have appeared, so much so that it can be difficult to find your way around. Don't panic, this article is here to help you.
Definition
Let's start by defining the different types of drivetrains:
Front-wheel drive or FWD Only the front wheels are driven. The vehicle is therefore pulled by the front axle. Examples: Ford Fiesta, Mazda CX-3, Mini Cooper, VW Golf GTI
Rear-wheel drive or RWD Only the rear wheels are driven. The vehicle is pushed by the rear axle. Examples: Alfa Romeo Giulia Quadrifoglio, Ferrari 812 Superfast, Toyota Supra
Four-wheel drive or all-wheel drive or AWD Both the front and rear wheels drive the vehicle.
All-wheel drive can be permanent, meaning that all four wheels are driven at all times. This is the case with the Quattro from Audi, for instance. Examples: Audi RS6, Lamborghini Aventador, Land Rover Defender, Subaru XV
In the case of a non-permanent all-wheel drive, only one axle is continuously activated. The second axle is only engaged when it is deemed necessary, such as in the event of a loss of traction. The Haldex system, which is used in many VW products, is a non-permanent all-wheel drive. Examples: Ferrari GTC4Lusso, VW Golf R
A manual all-wheel drive must be, as the name suggests, manually activated. When this is not the case, the vehicle is rear-wheel drive or front-wheel drive. Example: Dodge RAM
Historical background
Before discussing the advantages and disadvantages of each system, let's look at their origins. Originally, cars were rear-wheel drive. Front-wheel drive was only popularised in the 1930s. Citroën were the first to market a front-wheel-drive vehicle on a large scale with their Traction Avant. At first, the four-wheel-drive system was limited to off-road vehicles. It was not until the 1980s that the technology became more widespread after Audi proved its effectiveness in the World Rally Championship. Subaru also contributed to this process.
Today, the majority of cars are front-wheel drive. Four-wheel drive vehicles are also very common, especially in mountain regions. Many sports cars are also equipped with four-wheel drive. Rear-wheel drive is following a downward trend and is mainly used for sports cars.
Front-wheel drive
Advantages
Most standard cars today fall into this category. The main reason for this is the simplicity of the system. In general, the engine is positioned on the front axle. Thus, the distance between the engine and the wheels is small, which reduces production costs.
This drive system is very safe. This also explains why it is the most popular. However, front-wheel drives tend to understeer (widen the trajectory when cornering). Yet, this effect can be reduced by simply letting off the throttle.
Disadvantages
The fact that the front axle has several functions (steering, traction, damping) hurts the dynamics and handling of the vehicle. This results in loss of traction, vibrations in the steering wheel, etc.
Rear-wheel drive
Advantages
The main reason why many sports cars are rear-wheel drive is because of their traction. When accelerating, the vehicle swings backwards and transfers its weight to the rear wheels. This transfer of force logically increases the grip of the rear axle.
Driving pleasure is generally greater in rear-wheel drive vehicles. As the power is sent to the back wheels, the rear end of the vehicle tends to slip when cornering (oversteer).
Disadvantages
The fun aspect of this drive system, however, increases the risk of loss of control and spinning. This danger is increased when the road surface is slippery. In addition, rear-wheel drives are not known to be good on snowy roads and are difficult to control in poor driving conditions. However, advances in electronics have reduced these shortcomings.
Four-wheel drive
Advantages
Cars with all-wheel drive have excellent traction, which improves performance on and off the road. That's why most powerful modern cars are equipped with it. In addition, when road conditions are bad (snow, rain, etc.), it is the most efficient transmission.
Each manufacturer is free to emphasise safety or sportiness via the system settings. When the majority of the power is transmitted to the front wheels, the vehicle will be safer. In the opposite case, driving pleasure will be prioritised.
Disadvantages
All-wheel drive is more expensive. Apart from the higher fuel consumption, partly due to the increased weight and friction caused by the extra parts, tyre wear is increased. During acceleration, not two tyres are worn down by the traction forces, but four. In addition, all-wheel drive cars are generally more expensive to buy than their front- or rear-wheel drive counterparts.
Four-wheel drive systems can reduce the space inside the vehicle, especially in the boot. This is due to the additional parts.
Some hybrid cars combine an electric motor on one axle with a combustion engine on the other. Although this reduces the fuel consumption of the vehicle, it increases the weight and complexity of the whole package, which can hurt reliability.
Conclusion
Each system has its advantages and disadvantages. They can be summarised as follows:
FWD is safe and economical but does not offer the best dynamics
RWD is fun, but harder to control and not very effective on slippery roads
AWD offers the best traction but is more expensive to buy and to run
When buying a car, it is important to take these aspects into account. If you can't decide on your new or used car or need support, contact Carequest!
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