4WD: How It Works

There are so many things to consider when shopping for a new car that it can really be kind of overwhelming. One of the most important factors is choosing the right drivetrain. Specifically, do you want two-wheel, four-wheel, or all-wheel drive? Many people don’t really know the difference between four-wheel and all-wheel drive. Read on to find out more about how these drivetrains work so you can make your next car purchase confidently.

All-Wheel Drive

All-wheel drive (or AWD) is a common feature on sporty cars that aren’t necessarily off-road vehicles. AWD is more common on small cars than it is on larger vehicles like a truck. A modern AWD system improves performance, handling, fuel efficiency, and safety. An AWD system provides power to all four wheels at the same time. The whole thing is controlled by an advanced computer system that does much more than just power the transfer case. An AWD system monitors and distributes the power for different drive conditions and situations. For instance, when making a turn at high speeds, the computer might transfer power to the inside wheels for added traction. It could also transfer power to your front wheels when driving down a steep incline. Basically, the torque for each wheel will vary to optimize performance for all types of driving. These systems are smart and intuitive. A modern AWD is particularly helpful in wet conditions. It redistributes power to the wheels to ensure it has maximum traction and stability. A car with AWD is a smart decision for climates that receive rain and light snow. That is, if you drive mainly on plowed roads during winter snow, an AWD system will be very safe and reliable.

Four-Wheel Drive


Image via Flickr by Petr Magera

A four-wheel drive (or 4WD) system provides equal power to each wheel when it is activated. Most cars and trucks with 4WD capabilities are really 2WD with a 4WD setting. That is, you need to turn the 4WD on. You don’t need 4WD in most situations because it uses more gas and wears down your tires more quickly. When 4WD is activated, power is equally dispersed through the transfer case so that each tire receives the same torque. This is very important for off-roading and muddy, snowy, or sandy conditions. Of course, 4WD is most common on trucks and SUVs. It is the perfect system for weekend adventurers. 4WD can be a huge advantage for many drivers. It is great for driving on unplowed snow. It is perfect for dirt roads and steep inclines. More extreme 4WD drivers climb rocks and put their vehicle to the test. You might think that having 4WD is unneccessary, but having the capability, even if you hardly ever use it, is a huge perk. You can go just about anywhere with a 4WD automobile. While AWD might be more suitable for everyday driving, 4WD can take your new car or truck to the next level. The ultimate package is one that has AWD with 4WD capabilities. This is common (but expensive) on most modern trucks and SUVs.