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The automotive world is full of misinformation, old myths, and half-truths – and nowhere is that more apparent than in conversations about the drivetrain.

Front-wheel drive, rear-wheel drive, all-wheel drive, and four-wheel drive are your options. Each have advantages and disadvantages that should be understood by smart auto shoppers. While most shoppers understand the difference between front-wheel drive and rear-wheel drive, the distinction between four-wheel drive and all-wheel drive can trip up even savvy buyers.

Here is what you need to know:

Why They Exist

In a word: Traction.

Whether it is a four-wheel drive or all-wheel drive system, the point is to increase traction during acceleration.

On a performance car like the Audi R8, the all-wheel drive system helps the car accelerate faster by sending power to all four wheels, reducing the strain on any one wheel and thereby reducing wheel spin.

On an off-road vehicle like the Jeep Wrangler, four-wheel drive insures that if one tire loses traction in the mud, or if a drive wheel isn’t even touching the ground, the other three wheels can pitch in to help pull the vehicle out of trouble.

All-Wheel Drive Is for Cars and Crossover SUVs

In all-wheel drive vehicles, all four wheels are getting power all the time, though not in equal amounts. Some all-wheel drive systems send more power to the front wheels, and some send more to the rear (usually this rear bias is for performance cars). Modern all-wheel drive systems with torque vectoring vary the amount of power sent to each wheel as they react to input from the road and driver. In vehicles so equipped, handling capabilities can be increased significantly. This is the reason all-wheel drive is so common on modern performance cars. All-wheel drive also tends to be cheaper, lighter, and less complicated to operate than four-wheel drive, hence its popularity on family vehicles like crossover SUVs.

Four-Wheel Drive Is for Trucks and Off-Roading

Four-wheel drive is best known for helping off-road vehicles, like the aforementioned Wrangler, traverse terrain that everyday drivers would never think of. The most important thing four-wheel drive does is send power to all four wheels equally. Having equal power across all four wheels makes easy work of low-traction situations. 

Since trucks often need to stray off the beaten path, almost every vehicle in our compact and full-size pickup truck rankings offers four-wheel drive. Some trucks, like the Chevrolet Colorado and Toyota Tacoma, offer off-road-specific trims that come with features we’ll discuss below. 

Fiat Chrysler Automobiles

There are two main types of four-wheel drive: part-time and full-time. Part-time four-wheel drive gives you the option to drive all four wheels but normally operates in two-wheel drive to save gas. Full-time four-wheel drive distributes the engine’s power to each of the wheels all of the time.

Four-Wheel Drive Can Have Extra Features for Off-Roading

Some four-wheel drive systems have locking differentials, which can help you negotiate slippery terrain, and low-range gearing (as part of a two-speed transfer case), which can help you crawl over rocks at slow speeds. You don't want to use them on regular pavement though. A vehicle won't turn smoothly with a locked differential, and low-range gearing is only meant for very slow crawling.

You’ll also find skid plates underneath a four-wheel-drive vehicle to help protect the underbody from rocks, stumps, and other rough features. They can also come with automated systems that can adjust how the vehicle drives based on what type of terrain you’re traversing. 

Downsides to All-Wheel Drive and Four-Wheel Drive

Sending power to all four wheels adds extra mechanical components between the engine and the road, and it adds weight. As a result, four-wheel-drive and all-wheel-drive cars get worse fuel economy than their two-wheel-drive counterparts. They also tend to be more expensive.

All-Wheel Drive vs. Four-Wheel Drive in the Snow

When it comes to driving in the snow, you can lose traction and spin out no matter which drivetrain you choose. The biggest factor in determining whether or not you stay on the road during snowstorms is your speed and the tires you use. You can read more about which tires are the best for which driving situations by clicking here.

All-wheel drive, like we mentioned earlier, has all four wheels spinning continuously to keep your vehicle stable and on the road. Some all-wheel drive systems can change the amount of torque automatically, making sure your tires don’t slip, spin, and lose traction.

Four-wheel drive is better suited for deep patches of snow or rugged, icy terrain. If you live pretty far north, it’s probably better to go for a four-wheel-drive vehicle over an all-wheel-drive vehicle.

The Bottom Line

All-wheel drive and four-wheel drive systems are popular options, but most drivers will do just fine without spending the extra money to get them. Unless you are off-roading or live in an area with deep, long-lasting snow, a good set of winter tires is likely all the extra traction you’ll ever need.

If you do want all four wheels to be driven, all-wheel drive is probably better. It's available on more vehicles, cheaper, less complicated, and easier on your gas budget. Unless you need serious off-roading power, four-wheel drive is unnecessary.​

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