The Essential Features for Your Off-Roading Adventures

When taking the road less travelled, it’s important to understand some of the essential features for off-roading. No matter what kind of terrain you plan to encounter, there are certain specifications of a 4WD that could take your off-roading experience to the next level. We’ve narrowed down a few of the most game-changing features below.

1. Sufficient Ground Clearance and Approach, Departure and Breakover Angles

Ground clearance, also known as “ride height” refers to the minimum distance between the lowest point of the body of your four-wheel-drive and the ground. When tackling particularly rough and uneven surfaces, decent ground clearance is something you’ll want to look out for. Without it, you’re very likely to cause some serious and expensive damage to the under-carriage of your vehicle by coming into contact with any raised obstacles like boulders or tree stumps.

Your 4WD’s approach angle determines the steepest hill it can climb without the front bumper making contact with the ground. This means that vehicles with a shorter overhang (the distance between the front wheelbase and the front bumper) will have a better approach angle and take on sharper climbs.

The breakover angle will determine the steepest obstacle you can traverse without “high-centering” or hitting the underside of your 4WD and becoming stranded. This is the angle between the bottom of your tyres and the centre of the vehicle's underside and is slightly different to ground clearance which is measured from the lowest point of the vehicle body.

Similar to the approach angle, the departure angle will determine the steepest angle possible you can navigate before hitting the rear bumper. Again, vehicles with a shorter overhang on the rear bumper will have a better departure angle.

Let’s compare:

A standard hatchback type car with modest angles might have an approach angle of 19.5 degrees, a breakover angle of 19 degrees, and a departure angle around 21 degrees.

The Suzuki Jimny, on the other hand, has greater angles that will allow for more heavy-duty off-roading. With an approach angle of 37 degrees, a breakover angle of 28 degrees, and departure angle of 49 degrees, you can understand how the Jimny might be more capable when tackling difficult situations.

2. High Range and Low Range Gear

In 4H (four-wheel drive, high range) all four wheels are driving your vehicle. You use 4H for when you leave tarsealed roads and you need greater traction on firm sand, dirt roads, and gravel tracks.

In 4L (four-wheel drive, low range), all four wheels are driving your vehicle and a low gear ratio is being used. The low-range gear in a 4WD engages the wheels with additional torque and is most effective when you need to move at slower speeds. This maintains momentum without overwhelming the engine, and efficiently controls the weight of the vehicle in the initial start up to help avoid slipping.

The 4L or low-range setting will make a huge difference when traversing soft sand, deep mud or snow, through shallow water, up steep hills and declines and rock-crawling. Pretty much anywhere you need maximum traction and controlled power - but, it’s important to switch into low range before you need it via the dial or knob in the cabin.

3. Locked Differential or Limited Slip Differential

If you’re an avid off-roader, it’s likely that you’ve heard of a locked differential (diff lock) or a limited slip differential (LSD). The main function of a locked differential and limited slip differential is to help you navigate through sand, mud, water on uneven terrain.

The main difference between the two is that the locked differential forces both left and right wheels on the same axle to rotate at the same speed under nearly all circumstances. This is great for serious off-road use but is not suitable for use on firm surfaces as it places stress on the driveline due to the “binding up” when cornering as each wheel is trying to turn at different speeds to each other.

In comparison, the limited slip differential allows its right and left axles to rotate at different speeds but limits the maximum difference between them. The locked differential is suited for those vehicles which are predominantly used in serious 4WD situations while the limited slip differential is more flexible when transitioning from open road to high traction surfaces.

If you have electronic brake LSD such as found in the Suzuki Jimny, the traction control system prevents the vehicle losing drive when two wheels diagonally from each other start skidding or losing traction. The brake LSD traction control automatically brakes the slipping wheels to redistribute torque to the other side and allow the vehicle to gain traction with the wheels that are still gripped to the terrain.

4. Hill Descent Control

When you’re travelling down a steep slope and engine braking isn’t enough to slow the vehicle, hill descent control gently applies the brakes and helps maintain a slow and controlled speed down the slope. This allows the driver to concentrate on steering while keeping the wheels turning at a manageable speed.

Hill descent control systems are usually activated by pressing a button which then shows the system is active on the dash display. On some vehicles you can set the descent speed from as little as 2km/h, and the car’s braking system takes care of the rest. The system will slow the vehicle to the speed selected, and you can usually feel and hear it working.

The speed of the car is calculated from averaging the speeds of each of the four wheels and the braking is more precise and effective than manually applying it yourself while trying to operate the clutch and brake pedals. This allows the driver to focus on steering your way out of trouble. When you touch the accelerator or brake, the system cancels and reactivates when the pedal is released.

Extreme 4WD Features

Mud Terrain or All Terrain Tyres

Not all tyres are created equal, and when it’s time to go off-road, it pays to choose wisely. The two types that are most often associated with off-roading are All Terrain tyres, usually written as A/T, and Mud Terrain tyres, or M/T, also known as Mud Grip tyres.

Mud Terrain tyres are easy to spot out in the wild thanks to their large size and extremely chunky tread - but you’re likely to hear them before you see them. These tyres are made for heavy duty off-roading, and are capable of finding grip when you’d least expect it. The open tread pattern digs for traction over loose, rocky terrain, and then ‘self- cleans’ by letting go of rocks as the tyres rotate. However, while they handle well in an off-road environment, Mud Terrain tyres are not as capable of gripping to tarmac because of the design of the tread.

That’s where All Terrain comes in. If you’re looking for something more versatile, these tyres are well suited to a variety of situations. Thanks to their deep but balanced tread, they not only handle off road terrain such as light sand, mud, and rocky ground, they also offer a much higher level of grip and comfort on the road than a mud tyre would. Most manufacturers recommend a split of 60% on road to 40% off road, but the quality and versatility can vary depending on the brand - so a little research goes a long way.

Under-carriage protection

The underbody of your 4WD is one of the most exposed areas when it comes to off-roading, and can be an easy target for rocks and obstacles. The standard protection might protect against stone damage, but you’ll need something more heavy duty when traversing over stumps, rocks and ruts.

Under-carriage protection in the form of thick steel or metal guards are bolted securely to the chassis of the vehicle and are designed to keep some of the most valuable components safe from damage, including your steering, transmission, sump and differentials.

Investing in underbody guards may be the difference between getting your vehicle home undamaged, or lying busted out on the track.

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