FWD vs. RWD vs. AWD: How the wheels that turn change the way you drive
Front-wheel drive (FWD), rear-wheel drive (RWD), and four- or all-wheel drive (4WD or AWD): you’ve probably heard these terms kicked around before. These are the three main types of engine and transmission layouts for motor vehicles and it’s one of many key ways vehicles are classified and grouped. There are many methods of vehicle classification, but this method essentially is one of the more prominent, as it separates them based on which axle the engine and transmission sends its power to (the drive wheels).
Obviously, not all layouts are created equal and they certainly all do not perform the same. That’s because each layout comes with its own inherent handling characteristics, significantly affecting the way a vehicle handles and behaves. Though handling isn’t just affected by which axle(s) receive power. The handling behavior of each layout is also affected by where the engineers specifically place the engine. That’s because it can alter the weight distribution of a vehicle, playing a huge role in handling, especially in inclement weather or during high-performance driving.
So, what do these terms mean, especially in terms of road-handling performance?
Overall, each layout generally has its own reputation. But before we get into that, let’s go over the basics.
What is rear-wheel drive (RWD)?
Rear-wheel drive, abbreviated as “RWD,” is the oldest type of vehicle layout, where simply, the engine sends its power through a transmission to the rear axle of a vehicle. Its origins date back as far as the first automobile, as far back as the 1885 Benz Patent Motor car from the initial days of Daimler-Benz (what we now know as Mercedes-Benz) and the 1895 Panhard, a company that essentially predates PSA Peugeot Citroen.
What is front-wheel drive (FWD)?
Front-wheel drive, or abbreviated as “FWD,” basically means that the engine sends its power to the front set of wheels. Front-wheel drive surfaced in the 1900s in various prototype forms and is also French in origin, and only really existed in the early years of motorsports. However, the first truly successful production vehicle application of front-wheel drive surfaced thanks to a small British automaker called Birmingham Small Arms Company. Other companies from Germany and America took notice and began adopting the design themselves. Over the years, notable front-wheel drive vehicles include early vehicles from Auto Union (now known as Audi), Citroen and its famous 2CV, and more. It wasn’t until the 1970s that front-wheel drive truly became popular due to the formation of Corporate Average Fuel Economy rankings after the 1973 Oil Crisis.
What is all-wheel drive/four-wheel drive (AWD/4WD)?
All-wheel drive and four-wheel drive, abbreviated as either “AWD” or “4WD,” basically means the power gets sent to all four wheels for the utmost traction. While “four-wheel drive” can be used to describe a specific type of system usually found on trucks, it can also be used as a general term that also encompasses “all-wheel drive,” just to basically describe that a vehicle sends its power to all four of its wheels. Four-wheel drive originated mainly for use in utility vehicles, trucks, and SUVs. But thanks to the advent of all-wheel drive, which is significantly different to truck-based four-wheel drive systems, all-paw traction is now more readily available on normal road cars, such as sedans, wagons, and even SUVs. See our piece on the specific differences between “four-wheel drive” and “all-wheel drive.”
Which is better?
Ah, one of the most loaded questions and hotly debated topics in the automotive world. The truth is, it really depends on the situation and the application of the system. For instance, any type of four-wheel drive system is perceived as superior for any sort of low-traction situations. That makes it most favorable for those who live in regions where it snows quite a bit, or where paved roads are a luxury. More recently, all-wheel drive has become more prominent in performance applications for the sake of increased traction.
When it comes to two-wheel drive layouts and the argument of front-wheel drive versus rear-wheel drive, the debate becomes even more complicated. Because of its age and history with the origin of the automobile, rear-wheel drive was once the most prominent type of drivetrain because of its simple and cost-effective design. Though as technology evolved, cheaper development costs made front-wheel drive more popular due to packaging and fuel economy. That’s because front-wheel drive vehicles require less parts since the power- and drivetrain are typically all one unit that sits at the front of the vehicle. There’s no such thing as a rear-engine, front-wheel drive vehicle because it makes zero sense in terms of engineering complexity.
As for which is better, well, again, it depends on the situation. Both front-wheel drive and rear-wheel drive vehicles have their disadvantages, but both have proven themselves well, especially when the car is equipped with the proper tires for the weather.
Bred for the right conditions
The focus of comparison really involves how well they perform during inclement weather. This issue is what concerns most vehicle buyers as they want a car that can get them from point A to point B reliably. Any four-wheel drive vehicles are typically preferred since they’re typically “all-weather” vehicles and can be driven in any situations. But not every car comes with a type of four-wheel drive and they often demand a price premium.
So, as between front and rear-wheel drive, if you had to really split hairs
Front-wheel drive vehicles tend to perform better in everyday driving situations, particularly during inclement weather. That’s because both the engine and the transmission sit over the front axle, adding weight to the drive wheels, which increases traction for slippery situations. Most manufacturers of standard cars have resorted to front-wheel drive because they’re cheaper to make, more efficient in operation, and provide better traction to the everyday driver.
Rear-wheel drive vehicles, despite being the original layout and preferred in the earlier days of motoring, have disadvantages to the everyday driver and become trickier to handle when bad weather sets in. Not everyone is capable of handling a rear-wheel drive vehicle during inclement weather.
It’s not as clean-cut as some might like, but in many ways, your environment and daily routine will dictate which drivetrain is right for you. The biggest factor to consider would be if you live in either a fair-weather or mild four-season climate (modest levels of snow and rain), the truth is that you can get away with pretty much any drivetrain choice.
Performance driving behavior
When it comes to driving fast and motorsports situations, such as on racetrack or on a dirt rally, all three layouts have their advantages and disadvantages. But mainly, they all differ in term of how they’re handled by the driver, particularly at the limits of adhesion. Front-wheel drive vehicles are often stigmatized because they handle differently than rear-wheel drive vehicles.
Front-wheel driven vehicles tend to exhibit what’s called “understeer,” or when the vehicle resists its own ability to steer because the front axle is overloaded. This is what we know as the sensation of “turning the steering wheel and nothing happens,” and Newton’s first law of inertia physics comes into play. That’s because front-wheel drive vehicles put a lot of demand on the front axle, requiring it to both deliver power and manage steering, which can easily overwhelm the front tires.
Truth be told, front-wheel drive and rear-wheel drive both have proven themselves as tried and tested in motorsports. Examples of legendary front-wheel drive racing includes the original Mini Cooper during the famous Monte Carlo Rallies and more recently, the British Touring Car Championship, which almost exclusively features front-wheel driven racing cars.
Rear-wheel drive is preferred in performance applications since its layout offers the most flexibility and versatility without any sacrifice in performance. In other words, rear-wheel drive cars can have their engine sit either at the front of the car, in the rear-middle of the car, or in some unique cases, the rear of the vehicle (like the Porsche 911 or original Volkswagen Beetle).
For performance drivers, it also provides the most “balanced” feel, wherein vehicle handling characteristics of rear-wheel drive vehicles are very predictable with the right talent behind the wheel. That’s usually due to weight distribution and the fact that you’re not asking a set of wheels to do more than one action. Also, because the rear wheels are the drive wheels, they often exhibit what’s called “oversteer,” which occurs when the rear of the vehicle rotates around a curve because the rear drive wheels lose traction, causing the weight of the vehicle to shift and break the rear end loose. For performance drivers, this is preferred over understeer since oversteer can be recovered a lot more easily again, if you know what you’re doing behind the wheel.