Is All-Wheel Drive Really four-Wheel Drive?
What's the difference between four-wheel drive (4WD) and all-wheel drive (AWD)? My new neighbor asked me that the other day. And just so I could finish the conversation and get back to bench pressing a transfer case into place, I said that some cars have AWD and most trucks have 4WD. Yes, it was a simple answer to a very involved question, but I'm not 18 anymore and that transfer case was getting heavy on my chest. But once again it got me thinking about the vast majority of people who have no clue about the difference, as well as the common misconceptions of the terms and how the automotive industry confuses the masses with even more inane phrases, such as automatic electronic real-time 4WD. What? What the heck is that? OK, to end the confusion that abounds in the media, here's a brief primer on the terms, and how they should accurately be used.
The first term we all love is 4WD. This was intended to mean that all four wheels of a vehicle are powering the car. This is true to an extent, and the term 4x4 also means four-wheel drive of all four wheels. Likewise, a military 6x6 means six-wheel drive on all six wheels. In reality though, this only happens on level ground with equal tractive surfaces on all tires. This also means the 6x6 doesn't have 4WD, unless two wheels are off the ground. For instance, any two-wheel-drive car equipped with an open differential is actually only a one-wheel drive when the opposing tire is in the air, and you couldn't drive it away. Conversely, a 4x4 sporting open differentials with one tire from each axle in the air also only has two tires driving (the ones in the air), and not only is stuck, but would be a 2x4 or a 4x2 at any rate. So any manufacturer of a 4x4 with open differentials should more accurately call its rig a 2WD instead of a 4WD.
So now that we've established that almost nobody makes a true 4x4, how about that AWD designation? In this industry, we've loosely applied that moniker to such cars as an Audi Quattro or AMC Eagle or any minivan that drives all of its wheels. And that is totally bogus. Heck, International Scouts had nearly identical drivetrains as Jeeps in the early '60s, and the Jeeps were called 4WD and the Scouts were called AWD. Yep, right there is pure marketing hype. There is no difference. Remember, a military 6x6 is also an AWD, and so is a 4x4 Jeep with 4WD. The reason most lazy automotive writers and confused corporate marketing executive types started to use AWD in the wrong manner is that they used the term AWD for a 4WD without low range in the transfer case, or in a full-time system where the front axle was always engaged with the rear. Heck, does that mean my Jeep is actually a 2WD that morphs into an AWD when I engage the frontend, and then magically changes again to a 4WD when I shift into low range? Cool! That means I have three different vehicles, and I only have to insure one of them. Don't you just love marketing?