2017 Jeep Grand Cherokee TrailhawkAutomotive News Head to Heads & Advice 

Drivetrains Matter: All-Wheel Drive vs. Four-Wheel Drive

When you’re looking into what kind of drivetrain you want, you’ll be happy to know there are several kinds from which to choose. Today, we’ll help you understand the difference between all-wheel drive (AWD) and 4x4s (four-by-fours, also known as four-wheel drive and 4WD).

Choosing the right kind of drivetrain matters, and knowing the difference between AWD and 4WD is key to being able to tackle the kind of roads (or lack thereof) you want to get into. Continue reading to learn more about all-wheel drive vs. four-wheel drive.

 

All-Wheel Drive

This system utilizes all four wheels, thus all-wheel drive, either part- or full-time. Power from the engine is sent down the driveshaft to the front and rear axles, usually with a differential between the two axles to send power forward or rearward when traction is lost.

However, not all all-wheel drives are the same.

Part-time all-wheel drive has a drive shaft that can disengage the front axle from the rear axle, making a vehicle front or rear-wheel drive. When the driver presses a button, the all-wheel drive is engaged. These kinds of AWD systems don’t usually come with a differential between the axles.

Full-time all-wheel drive is always engaged. Those with center differentials allow each axle to spin at a different rate. However, these kinds of vehicles aren’t really designed for serious off-roading. They can handle light off-roading on easy gravel or dirt roads, or snow on the roads.

Automatic all-wheel drive systems are similar to part-time all-wheel drive, however, the driver doesn’t need to do anything. The car’s computer automatically adjusts the drivetrain from two- to all-wheel drive when it senses slippage occurring.

Then there’s selectable all-wheel drive, where the transmission and drivetrain automatically adjust one of many selectable all-wheel drive settings, sometimes including 4WD modes and low-gear modes.

 

4-Wheel Drive / 4×4

On the more rough-and-tumble side of the aisle, there’s four-wheel drive (4WD, or 4×4). There are two kinds of systems of four-wheel drive, part- and full-time 4WD Systems.

Similar to part-time all-wheel drive, only one axle is active during normal driving conditions. A driver-selectable transfer case engages four-wheel drive mode, sending power to the front wheels along with the rear.

Full-time four-wheel drive systems usually send 25-percent of the engine’s available or needed power to each of the wheels. When the pavement ends and the crawling begins, a driver can lock the center differential and tackle any kind of rough terrain. Nearly all full-time, four-wheel drive systems come with high and low gearings for different kinds of off-roading.

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To check out either all- or four-wheel drive vehicles, please call or visit your local AutoNation retailer, today!

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