What Is The Difference Between 2WD, AWD, and 4WD?

If you don’t know anything about 2WD, you should know two-wheel drives are powered by either the rear wheels or the front wheels of the vehicle. You’ve probably heard the terms “rear-wheel drive” and “front-wheel drive”, and those are the two types of two-wheel drive.

A lot of rear-wheel drives are going to be muscle cars or pickup trucks. They don’t get around quite as well in winter road conditions. They tend to fishtail, which is why it helps to put weight in the back of one if conditions are snowy or icy. These vehicles perform much better under normal driving conditions.

On the other hand, front-wheel drives get around better in winter weather AND get better gas mileage, because the engine is usually smaller and directly over the wheels that power the vehicle. Front-wheel drive is what you’ll find in a lot of family vehicles, where performance isn’t as important as fuel economy and better handling when road conditions are less than ideal.

A four-wheel drive vehicle powers all four wheels, but it’ll typically be two-wheel drive UNTIL the four-wheel drive is manually engaged by a switch, a lever or shifter. In fact, driving in normal conditions with four-wheel drive engaged can actually cause problems. A lot of four-wheel drives have two settings: a low gear for things like off-roading or pulling boats out of water, and a high gear for driving on snowpack or other slick road conditions. In addition, a 4-wheel drive vehicle may offer locking differentials. This would send power to both wheels of an axle equally.

Now, most people, when they think of four-wheel drives, think of huge trucks, SUVs or off-road vehicles with big, knobby tires and high ground clearance. And that’s because four-wheel drive IS designed for the most extreme conditions and off-road driving.

Four-wheel drive can also come in handy if you ARE trying to pull a boat or trailer up a slippery ramp or gravelly incline where a two-wheel drive may not give you the traction you need. And maybe this goes without saying, but a four-wheel drive is going to handle muddy situations better than other vehicles. Some people buy one just for playing in the mud.

So lastly, an all-wheel drive will be either full-time or part-time. Full-time all-wheel drive is similar to four-wheel drive—since it does power all four wheels—but generally won’t have the option of a “low” gear for extreme situations like deep mud or snow. This option isn’t quite as common as part-time all-wheel drive, but it does give you better handling and traction at all times, since it’s full-time.

Part-time or “automatic” all-wheel drive works a little differently. This type is always on, but stays two-wheel drive until sensors detect the need for extra traction. When that happens, those sensors will then tell your vehicle’s computer to send power to the wheels where additional traction is needed. So, practically speaking, a vehicle that’s equipped with part-time all-wheel drive is going to be functionally two-wheel drive in normal driving conditions, and only utilizing additional traction a small percentage of the time.

The answer is probably, “No,” unless you’re really having trouble getting around in slippery road conditions. If you haven’t had any safety issues, you don’t intend to change the way you drive and you aren’t moving to a place where there’s more winter precipitation, you’re probably OK sticking with your two-wheel drive. The main thing that should make you really consider switching up to all-wheel drive is if you just haven't felt safe driving in bad weather conditions like snow or ice. These vehicles perform much better under normal driving conditions.

First, you are going pay more. An all-wheel drive version of the same vehicle will cost anywhere from fifteen hundred to four thousand dollars more. Also, because most all-wheel drive vehicles only send additional traction to wheels when it’s needed, you spend a VAST majority of the time driving in what is actually two-wheel drive.

Additionally, the extra weight of the all-wheel drive system—components like the transfer case, axles, differential and any other supporting gear—will decrease fuel economy. That weight is also likely to cause tires to wear faster than they would otherwise. And contrary to what you might think, all-wheel drive does not improve braking ability.

Lastly, in addition to the cost of lower gas mileage and greater tire wear, the all-wheel drive system is going to require maintenance and any costs associated with it.

The bottom-line difference here is that all-wheel drive is going to be the best choice IF you deal with road conditions that are slick on a regular enough basis that you need the stability of added traction. Whether that means you get a lot of rain, or you’re driving on ice or snowpack, an all-wheel drive system is going to give you the extra traction you need to get around safely.

Four-wheel drive, on the other hand, is usually designed with a more robust suspension and higher ground clearance. So it’s great for more extreme driving situations: mud, deep snow or snow drifts, or any kind of off-road driving or towing on surfaces that aren’t stable.