WRC cars have various components and technical requirements to be considered fit for competition, and one important component is the drivetrain system. You might therefore be wondering if WRC cars are AWD.
WRC cars are technically not AWD, as they are instead 4WD. The two drivetrain systems are similar, but there are some key differences between them, although both are ideal for rally racing. While many WRC cars have used AWD systems in the past, they must now use permanent 4WD drivetrains.
Understanding WRC car drivetrains is quite complicated, as 4WD and AWD systems can be used interchangeably, which can make it difficult to wrap your head around them. Below, we’ll be unpacking the differences between AWD and 4WD and discuss in detail what WRC cars are currently using.
Understanding AWD vs 4WD
The Different Drivetrains
Before we begin on the different drivetrains, let’s take a brief look at what a drivetrain is. The drivetrain is the system of components in a car that works to direct the power an engine produces to the wheels. It manages how this power is utilized by the car, and it also helps with stability and cornering.
The four different types of drivetrains are as follows: FWD, RWD, AWD, and 4WD. Generally speaking, you’ll often find different drive trains in different types of vehicles.
FWD
Front Wheel Drive (FWD) is found in the vast majority of mass-produced cars. This is because they are easier to make, they maximize the space in the car (giving more space in the car cabin), and are just generally cheaper and easier to maintain, which makes them perfect for most manufacturers and the vast majority of drivers.
The issue with these kinds of drivetrains is that they are prone to understeer, have less towing capacity, sluggish acceleration, and are more prone to wear and tear. However, these aren’t dealbreakers because most people won’t be driving their cars in incredibly difficult conditions. For your average driver on an average road, this is a great drivetrain system.
RWD
Rear Wheel Drive (RWD) is often found in racing and performance cars. RWD comes with some pretty solid boons, as it’s generally a better handling and driving experience on smooth roads. Things change for the worse when the roads get difficult, or there’s lots of variation in hills and climbs.
There are also some hefty cons to RWD, as they have lower traction, less interior space due to needing more components, less cargo space, greater expense, and lower fuel efficiency (as a result of the drivetrain being heavier than FWD).
AWD
This is where things get a bit confusing, because marketers and car enthusiasts will often use 4WD and AWD interchangeably. Some will often say the differences are limited because they both work using similar principles.
All Wheel Drive (AWD) uses electronic sensors and a central differential to constantly provide engine power to both the front and rear wheels of a car, depending upon what the front and rear wheels are doing. Theoretically, it gets you some of the benefits of a 4WD without the costs.
In practice, AWD can help a bit on slippery or icy roads, as they will automatically engage when there’s a discrepancy in the traction at the front and rear wheels. You’ll often find SUVs marketed with an AWD system, as they can help drivers in difficult conditions or inclement weather.
AWD Confusion
How good AWD is really dependent upon the individual car manufacturer itself (for example, Subaru and Audi are renowned for having good AWD systems). It realistically depends on how well the sensors are programmed and how well the system is integrated into the rest of the car components.
There are various ways to program AWDs, and many manufacturers will use them to improve vehicle safety. They do this by programming the sensors to help correct under and oversteer and then connect it to the ABS (anti-lock braking system).
AWD cars have a central differential (the component that manages the power being sent to each axle). The differential sends power to either the front or rear of the car, depending upon what’s needed, but it is not the same as a dedicated 4WD system. There are also full and part-time AWD systems, with the latter only kicking in when needed.
4WD
Four-Wheel Drive (4WD) can often be found on jeeps and vehicles designed solely for off-roading. This is because they provide the most traction and “stick” the car to the road, even on roads or terrain that’s wet, sandy, or otherwise uneven.
The 4WD system uses a transfer case that sends equal amounts of power to the front and back of the vehicle. This is one of the key differences between a 4WD and AWD system. AWD uses sensors and a central differential, while a 4WD system uses a transfer case to send power to the axles.
The main disadvantages of 4WD are that it noticeably reduces fuel efficiency, and maintenance is more expensive due to extra expensive parts. It will, however, drastically improve traction and control off road, and more experienced drivers can get higher levels of performance out of their vehicles in challenging terrain.
AWD vs 4WD
Manufacturers and car enthusiasts alike will often state that the AWD and 4WD systems are interchangeable and the same, but this isn’t technically correct.
While 4WD is much more reliable in rough terrain, it greatly increases the expense of the vehicle. It requires a lot more components to build a 4WD drivetrain, and it often requires a car to be designed around this system.
Are All WRC Cars AWD?
All WRC cars have had some kind of AWD system, whether that’s because of an AWD system or a 4WD drivetrain. It’s practically impossible to compete in WRC competitions without the advantages these drivetrains bring. However, current WRC cars are technically 4WD.
A 4WD system brings with it a host of advantages that are hugely impactful in rally racing. From superb traction and control around tight, sometimes unexpected corners, to a greater level of performance across a variety of different surfaces.
RWD is great for performance on flat, reliable asphalt roads, but the moment you get some rain and mud, its performance and handling begin to suffer immediately. Time and experience have taught drivers and engineers that control under difficult conditions is what makes championship-winning rally cars, which is what 4WD excels at.
Past And Present
1985 saw the arrival of the Audi Sport Quattro S1, with the innovation of the Quattro AWD. This car tore the competition apart, completely obliterating its FWD and RWD rivals, and so competing manufacturers began to add either an AWD or 4WD drivetrain.
Between then and now, WRC cars have used some form of 4WD or AWD system, but in March 2020, the FIA released some of the technical requirements for the new generation of rally cars, which stated that cars had to be 4WD with six gears and NO central differential.
Technically speaking, all WRC cars must have a permanent (always active) 4WD drivetrain, so they are not specifically AWD, as AWD relies on a central differential. You might find this confusing as some people still use the terms 4WD and AWD interchangeably, but WRC cars are now all 4WD. This applies to all the WRC leagues (WRC, WRC2, WRC3, and Junior WRC).
KEY POINTS
• Most production cars use a FWD system
• Many people may use the terms AWD and 4WD interchangeably, but there are differences
• All WRC cars use 4WD systems
Do Rally Cars Have To Be AWD?
Not all rally cars have to be AWD, and in regional and national championships, you will often find cars competing with FWD systems. This is because they’re cheaper to maintain and easier to learn in, making these competitions more accessible for beginners.
Amateur leagues use FWD transmission systems for the same reason because of the higher number of components in 4WD cars (they need three differentials). Some drivers also use RWD, but it greatly depends on the individual driver’s preferences and the series’ rules.
Final Thoughts
WRC cars are technically not AWD, as they are 4WD. This is because the rules introduced in the 2020 season forbade the use of central differentials. However, regional and national championships will have FWD systems due to them being cheaper and easier to learn in compared to AWD/4WD.
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