Wheel drive of a vehicle can transmit force which is essential for changing the torque into tractive force. This force travels from the tire to the road and hence the vehicle moves ahead. Wheel drive can be broadly classified into two main types. The two types are – AWD and 4WD.
AWD vs 4WD
The main difference between AWD and 4WD is that AWD is present in every vehicle while 4WD is present in heavy-duty hauling vehicles or other extensive work activities. AWD stands for All-Wheel Drive system while 4WD stands for 4-Wheel Drive vehicle.
AWD has one axle which is permanently connected with the drive and the other is only connected when needed. AWD is always on and operates automatically. The fuel economy of AWD vehicles is comparatively lower.
On the other hand, vehicles with 4WD have a two-axled drivetrain that can provide torque to all the vehicles simultaneously. 4WD has to be manually switched by the driver and is not always on. The fuel economy of 4WD vehicles is higher than AWD vehicles.
Comparison Table Between AWD and 4WD
|Parameters of Comparison||AWD||4WD|
|Meaning||AWD stands for All-Wheel Drive system||4WD stands for 4-Wheel Drive vehicle|
|Off-road efficiency||AWD works fine for occasional off-roading excursions||4WD works fine for regular off-roading excursions and can even allow efficient driving in remote areas|
|Ideal users||AWD is ideal for riders of nasty weather and rough roads||4WD is ideal for users who perform heavy hauls on the job site|
|Advantages||The engagement of the driver with the system is not required manually, efficient road handling, has additional traction in slippery conditions and has improved fuel economy||4WD is ideal for off-roading conditions which include mud or sand, offers more versatility in conditions that required switching between drive modes, has a beneficial value while selling|
|Disadvantages||Higher upfront are expensive than conventional 2WD, the components of AWD has extra weight which reduces fuel economy, braking distances are not affected by AWD||Driver has to switch 4WD manually, Expensive models than traditional to AWD vehicles, vehicles with 4WD have less demand in the market, and requires high maintenance|
What is AWD?
AWD stands for All-Wheel Drive. Vehicles with AWD have a powertrain which is the power provider to the vehicle which can be on-demand or full-time. The on-demand type of AWD has one axle which is permanently connected with the drive and the other is only connected when needed. While the full-time, AWD has all the axles connected permanently and may or may not include a differential.
AWD may also be independent where the wheels are driven but does not depend on the central mechanical power coupling. All-wheel drive can be further divided into three main types. They are – four-wheel drive or 4WD, six-wheel-drive or 6WD, eight-wheel drive or 8WD. 4WD reflects two axles, 6WD reflects three axles and 8WD reflects four axles.
The use of differential is in a good road where the tire grip is better. This helps the axles to avoid driveline windup. It is not essential during off-roading as with limited grip also the tire can slip faster All-Wheel Drive vehicles built for off-roading do not usually have a differential which makes them suffer from wind up when they are on-roading.
With the sophistication of vehicles, it was decided to give the benefits of All-Wheel Drive in conventional cars in the year 1960. It was not applied for off-roading usage and was limited for winter use in snow or even on wet roads. The first high-speed road-based cars with All-Wheel Drive were Jensen FF, Subaru Leone, AMC Eagle, Audi Quattro, and various others.
What is 4WD?
4WD stands at Four-Wheel Drive. It is also known as 4×4 or four-by-four. Vehicles with 4WD have a two-axled drivetrain that can provide torque to all the vehicles simultaneously. It can be of on-demand or a full-time type. The linking of 4WD is with a transfer case that caters to an additional output drive shaft and can even provide gear ranges in some instances.
4WD is a type of AWD. 4WD has a set of particular functions and components which are designed for the off-roading application. 4WD has a compilation of modern use of the terminology. In the term four-by-four, the first figure signifies the total number of wheels and the second figure signifies the number of axel ends that are being powered. The vehicles with 4WD are equipped with transfer cases.
The function of the transfer case in 4WD vehicles allows the users to switch between the operating mode of 2WD or 4WD automatically or manually. The current usage of four-wheel drive is to light passenger vehicles and even to heavy vehicles, in North America.
4WD vehicles are even coupled with anti-slip technology which increases the hydraulic base and even allows spinning of differentials at different speeds. The application of 4WD is in vehicles used for road racing, construction equipment, or heavy trucks. The vehicles can operate not only in basic modes but also combine other types of modes.
Main Differences Between AWD and 4WD
- AWD can work automatically while 4WD has to be switched manually by the driver.
- The safety of AWD is higher since the system can automatically send torque to the wheel while the safety of 4WD is comparatively lower since the driver has to take the action manually during an emergency.
- AWD is found in crossovers and regular cars while 4WD is found in off-road vehicles like heavy trucks.
- AWD is not as robust as 4WD.
- AWD has no risk of axle binding while 4WD has the risk of axle binding and has to be turned off by the driver.
The drive wheel is a pivotal part of a vehicle and it results from the vehicle is moving forward or backward. The two main types of drive wheels are AWD and 4WD. Both types have distinct features and functionality. Both the types are operated in different ways by the drivers.
Both type of wheel drive are found in different types of vehicles. The traction type, fuel economy, maintenance, and performance are different in both types. The users should evaluate all the parameters before making a final decision with the vehicle.