It’s winter, people, which means fuzzy socks and hot chocolate and snuggling on your couch to watch not one, but TWO documentaries about the Fyre Festival. It also means single degrees and snowstorms and slippery roads—and, for those of us who drive on a regular basis, it’s a time to be extra-careful. It behooves us, then, to learn the difference between four-wheel and all-wheel drive—because despite the fact that the four wheels might be all the wheels, they are not the same thing.
Let’s ease into it. In two-wheel drive, or 2WD, torque is applied to either the front or rear wheels, depending on the type of vehicle. This is more suitable for driving in mild climates, where a car doesn’t have much need for real traction.
But both four-wheel drive (4WD) and all-wheel drive (AWD), as their names suggest, power all four of the vehicle’s wheels. So how do they differ? In all-wheel drive, the car sends a variable amount of torque to each wheel, depending on which wheels need it the most in any given moment. Four-wheel drive sends a fixed amount of torque to each wheel, which makes it much better for off-roading—but not as great for regular driving. That’s why most four-wheel drive vehicles have a two-wheel drive mode, and the driver can switch back and forth depending on the conditions.
It makes sense, then, that four-wheel drive is only found in SUVs and trucks that have higher ground clearance; these are the sorts of vehicles that you see fearlessly lumbering through the mud in football-game commercials. All-wheel drive, on the other hand, can be found in all types of cars and trucks, not just the off-roaders.
No matter what-wheel drive you have, stay safe out there!