March 6, 2017
The Modern Tech behind the 4 by 4 Off-Road Capability
Drive a 4 x 4 like a Land Rover or a Jeep Wrangler Rubicon on the city streets, and you’ll probably have a very nice ride. Yes, it’s comfy, you’ve got lots of space inside and in the trunk, and it even looks great. But this is its Clark Kent mode. Take it off the road and into rough paths, and you’ll see its Superman side in action.
Of course, the current off-road technology you see in today’s 4×4 vehicles haven’t always been with us. Check out a Jeep back in the mid-90s and you’ll see a very different picture. Back then, 4WD was available but vehicle computers weren’t. So everything was manual and analog, and it required a lot of muscle. Today, it’s all about pushing a button and letting the onboard computer do the figuring.
Let’s take a look at some of the technologies we take for granted in our 4×4 vehicles.
Shifting to 4WD by Pushing a Button
Nowadays, it seems like you can do most things in a vehicle with a push of a button. You want to roll your window down? Just push a button. It’s the same thing with switching to 4WD.
Back in the old days, though, there was no button to push at all. If you wanted 4WD capability, then first you had to actually get out of your vehicle first so that you can lock the front axle hubs. Then you go back in the car and pull that stubborn lever by your feet to engage the 4WD.
You have to do all these before you need the 4WD capability. If you wait before you get stuck in a muddy patch, then it’s more inconvenient for you. The mud may even get to the axles. And even if you do manage to engage the 4WD, you’re not really sure if you can get out of the muddy patch.
Today, those problems are a thing of the past. The 4WD knob or lever is much easier to turn and you don’t need to leave your seat. There’s no downside to it: there’s no vibration, you don’t use up more fuel, and the hardware doesn’t take up much room.
Automatic Traction Control
Your 4WD off-roader will undoubtedly have traction control too, and this system works by using the ABS (anti-lock brake system). The ABS has speed sensors on each wheel, so if a wheel starts to lock then the ABS modulates the brakes to avoid the lockup and the inevitable skid.
The traction control uses the ABS to apply the brakes to a spinning wheel that has lost traction. Then it transfers torque across the axle to the wheel that still has traction. In the old days, a truck on steep climb can get stuck once the wheels lose their traction. But now, you even have some traction control systems that match their responses to the kind of trail you’re traversing.
Electronic Locking Differentials
When you have an open differential, the left and right wheels on an axle can turn at different speeds when you turn at a corner. That’s because the wheels on the outside of the turn have to travel a longer distance, so that wheel needs more speed.
However, the downside to the open differential is that when you’re on a slippery track then the wheel encountering the least resistance gets most of the power. So if one of the wheels spins in the mud, then that wheel gets most of the power and you’re stuck there.
Now, however, you can push a button and you can get a limited-slip differential instead. This divides the power to all your 4 wheels, so even if one or two wheels get stuck then the other wheels still have the power to get you unstuck.
Adjustable Suspension Systems
Back in the day, you either get a suspension system that does well on city streets or out on the off-road track. You couldn’t have both. If you get a 4WD system, then driving on city streets isn’t really much fun.
But now, you can get both. Your 4WD vehicle may even let you control the swaybar. This bar limits the car’s body roll when you’re driving in the street, but it also limits your suspension movement when you’re on the track.
In some cars, you don’t even need to push a button to disconnect or reattach the swaybar. There’s a system that does that automatically when it’s needed.
All these advances in off-road capabilities are very much available to the average car owners. They’re not reserved for the very rich, since you can see these technologies in comparatively inexpensive vehicles. What’s more, these 4WD systems don’t make it any more difficult for you to cruise the city streets. It’s just that if you do want to blaze an off-road trail, then these 4WD technologies will make it just a lot easier for you!