In this article, we’ll go through the different ways vehicles’ engines power the tires, so you determine which type is best for you:
If you’re buying a vehicle, you may have heard terms like AWD, FWD, and 4WD thrown around. These refer to how your car sends power to your wheels to move it when you step on the gas. Uh-huh. So, what does that mean? How do AWD, FWD, 4WD, and RWD translate to what you need in a vehicle?
All-wheel drive (AWD) systems send power to both the front and the back wheels all the time. All-wheel drive systems can be found on a variety of vehicles and are not restricted to SUVs and trucks. There are two types of AWD systems:
Always active AWD: The first will always have the AWD system active, meaning that you’ll get power to all of your tires all the time.
Automatic AWD: The second is part-time or automatic AWD. In this system, power will only be distributed to all four tires when it’s needed. Most part-time AWD vehicles will have automatic sensors that detect how slippery or uneven the road is and enable AWD if necessary.
Let’s look at the pros and cons of AWD.
The main advantages of all wheel drive, are they are less intensive than four-wheel drive (also known as 4WD, which we’ll get to later) and are good on-road in inclement weather. An AWD car will still allow each tire to rotate at its speed during turns, which 4WD vehicles cannot. All wheels will receive torque in bad weather like rain, snow, or ice, and your car will handle far better.
It’s possible to go off-road in an AWD system, but it won’t be the best option, as you won’t have maximum engine torque sent to a single tire. AWD systems can suffer in fuel economy, as the engine has to work more to move all four tires. AWD systems can be thought of as the middle ground – good if you often drive on paved roads and worry about slippery conditions.
Front-wheel drive (FWD) is the standard way most engines power their tires to accelerate. A FWD car won’t have a driveshaft to send power to the rear wheels, instead, it uses the front two wheels to “pull” the rest of the car. Many mainstream cars and SUVs will have front-wheel drive systems.
FWD systems provide good traction in most weather, especially when compared to rear-wheel drive systems. FWD systems won’t have the same fuel economy issues as the aforementioned AWD system. AWD systems have more spacious interiors because of the room saved toward the back of the car that would normally be occupied by a driveshaft.
However, FWD systems don’t handle as well as rear-wheel drive systems on the road. They also are not good for off-roading, as you won’t have power in your back two tires in case your front two get stuck.
Four-wheel drive also referred to as 4×4 or 4WD, is a system that sends power to all four of a vehicle’s tires. Torque is delivered to all four wheels for the most amount of traction possible. Usually, this system will require the drive to shift into 4WD, which will lock the front and back driveshafts, so each tire is turning at the same speed.
With this active, the engine will provide torque to every tire. SUVs, trucks, and off-road vehicles like Jeeps will often have 4WD systems in either full-time or part-time options.
A full-time 4WD system will work similarly to an AWD, with the car’s systems controlling when power is applied to the front and rear wheels. With a full-time system, you’ll be able to lock the driveshafts for instances when you’re going off-road.
A part-time 4WD system will default your engine to powering the front of the back tires. Then, when heading off-road, you can engage the 4WD option and have all four of your wheels powered. This system allows for good on- and off-road handling.
Note that when 4WD systems are engaged, your car will not handle very well on pavement. It can potentially be dangerous and harmful to the car when turning, as car wheels rotate at different speeds during turns, and the 4WD system will shake and wear your tires as it attempts to keep all four tires rotating at the same speed.
4WD is the best possible choice for off-roading in very rough conditions. You will also get good performance in slippery conditions but will need to take turns very carefully.
AWD tends to be more on cars, crossovers, and small to midsize SUVs. Four-wheel drive tends to be more on light trucks, off-road vehicles, and larger SUVs. Is there an overlap between AWD and 4WD? Yes. In both systems, the engine powers both sets of wheels. Both systems and also be configured as full-time or part-time. AWD is designed to provide excellent traction on-road, especially in the snow. Four-wheel drive is designed to provide excellent traction on uneven terrain. The biggest difference is, that 4WD locks the front and rear driveshafts together (thank you, Driveway, for concisely explaining) so they receive equal power. Pair 4WD with rugged tires, like mud terrain or all terrain tires, and you’re ready to climb!
Rear-wheel drive (RWD) systems distribute power only in the rear of the car. This system used to be very common, as it saved space in the front of vehicles and distributed weight very well throughout. RWD systems also have a center of gravity that lines up with the driver for an increased sense of handling. It’s for this reason that many performance and sport cars have this system, as drivers can steer better when they’re turning.
RWD systems will often be found on luxury vehicles and are best for on-road maneuvering. While RWD is perfect for skilled drivers looking to pull off difficult turns and maneuvers, most drivers won’t find much benefit from this system.
RWD systems can perform well in slippery weather conditions, but you’ll need the correct tires for this situation. Also, a RWD system may not have as much weight naturally distributed toward the back of the vehicle as a FWD system does with the engine in the front. If you’re expecting to drive a RWD system, put some bags of salt or any other weight toward the back to increase traction.