What Is The Difference Between 4WD and AWD?

There’s a long list of confusing topics when choosing the right car, but all-wheel drive (AWD) and four-wheel drive (4WD) seem to consistently confound salespeople and car shoppers alike. Often, these terms are used interchangeably, but are they really the same? In the motoring world, they actually refer to very different systems, which can produce radically different results on and off-road. But let’s get to the point: how does 4WD — or AWD — impact your daily driving life, and which badge belongs on your car?

FOUR-WHEEL DRIVE (4WD).
Lets start with the old-school version. 4WD, sometimes referred to as Four by Four or 4×4, is typically used on off-road vehicles — or at least vehicles with all-terrain capabilities. Power goes from the engine, to the transmission, to what is known as a transfer case. This system splits power between the front and rear axles so that torque is evenly applied to each wheel. This process is nothing new, and is still used in modern Jeeps to tackle just about any off-road obstacle.
More contemporary 4WD systems are activated with buttons or switches rather than a manual lever, and include multiple settings for the 4WD system. These systems usually have two 4WD gears. 4WD ‘High’ splits power less evenly and allows what’s called ‘limited slip’ between the inside and outside wheels. This corrects the locked, spinning inside wheel problem by channeling more power to the wheel with traction (in our example, the outside wheel). 4WD High limits available power to the wheels so you can move quickly over slippery surfaces (up to about 60 mph). For the most available power, however, you’ll want 4WD ‘Low.’ The Low gear limits wheel speed but is perfect for arduous terrain. A word of advice: you really don’t want to go too fast in 4WD Low, things start breaking.
4WD Pros
Best traction in off-road conditions
Can be turned off to improve fuel economy
Proven, rugged technology.

4WD Cons
Adds weight and complexity to cars
Can't be used in all conditions
More expensive then two wheel drive models.

ALL-WHEEL DRIVE (AWD)
All-Wheel Drive is a much more recent innovation, and, as you might expect, much more complicated. It crops up on everything from supercars like the Audi R8 to grocery-getters like the Buick Encore.

The biggest difference between 4WD and AWD is that an AWD drive system is on all the time. Well, mostly.

There are two types of all-wheel drive: mechanical and electronic. The most common way of creating a capable, mechanical AWD system is by using three differentials. A differential is a box of gears, a.k.a. engineering magic, that can take power from the transmission and split it at different levels between two wheels (the front or rear axle) or four wheels (the front and rear axle).

In AWD, this system works to get power to the wheels with the most traction by splitting torque between the front and rear axles on the center differential, and to the individual wheels by way of the front and rear differentials.
AWD isn’t quite as robust as 4WD and it can’t match the acute power delivery necessary for low-speed off-roading (i.e. rock crawling). However, AWD does have some clear advantages.

AWD Pros
Provides increased grip and control under all road conditions
Gives sportier handling and traction to a broader range of cars
Works all the time

AWD Cons
Reduces fuel economy
Increases the weight and complexity of vehicles
Not as good in extreme off-road conditions

If you plan on using your vehicle off-road often, 4WD is definitely your best bet. 4WD appears on pickups and truck-platform SUVs that have the durability to match the ruggedness of a 4WD system. For most people, however, AWD makes more sense.

In the sort of dry/rainy road conditions that most drivers experience, it’s nice to have a drivetrain, like a modern AWD system, that responds instantly without the driver having to toggle any switches. In addition, most vehicles featuring AWD tend to have better weight distribution, which improves traction and performance. (Source digital trends).