Despite the increasing number of online resources and shifting dealer strategies, car shopping is still a bother. Add in all the new car segments, vehicle features, and technology acronyms, and the process becomes truly daunting.
There’s a long list of confusing topics when finding 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. 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 also referred to as Four by Four, or 4×4, is typically used on off-road vehicles – or at least vehicles with all-terrain capabilities.
Unfortunately, 4WD doesn’t fit neatly in a one-sentence explanation, but we’ll stick to the basics here.
Power goes from the transmission to what is known as a transfer case. This system then splits power between the front and rear axles so that maximum torque is going to each wheel. This power delivery process is nothing new, and still manages to propel modern Jeeps over, well, just about anything, but it does have some issues.
When the transfer case splits power evenly, it ensures that each wheel turns at the same speed. This is deeply problematic when doing things like turning. You see, for a car to make a turn, the inside wheel has to turn more slowly than the outside wheel, which is covering more ground. If the vehicle can’t do this, the inside wheel loses traction and it spins freely. This, as you might be able to guess, isn’t great for moving forward efficiently.
There are a couple of ways that modern 4WD systems get around this. For starters, most modern 4WD systems are only on when you activate them. This can be done electronically or by using that protruding lever that sits somewhere between your radio and the center console. That way, you can use 4WD at low speed in snow or mud, but enjoy the drivability of two-wheel drive in normal conditions. When left in 2WD, there are fewer moving parts, and therefore fewer restrictions to forward motion. Said a different way, you’ll save fuel when don’t need to engage 4WD.
The other, more refined 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 a 4WD ‘High’, which 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 to a point. Typically, however, High 4WD is recommended only up to around 60 mph. Flip these into ‘Low’, and they act much the same as old, locked systems. You really don’t want to try moving quickly in 4WD Low…things start breaking.
|4WD Pros||4WD Cons|
|Best traction in off-road conditions||Adds weight and complexity to cars|
|Can be turned off to improve fuel economy||Can’t be used in all conditions|
|Proven, rugged technology||More expensive than two wheel drive models|