You finally took the plunge and purchased your first four-wheel drive vehicle. Now, you’re ready to take your 4×4 SUV out for its first off-road experience. Not so fast. Before you head off to the back of Bourke and get yourself in a bingle, there are some things you need to be aware of.
First off, never take your off-road vehicle out if you haven’t checked it over properly first. You need to be aware of your front bumper, rear bumper, and undercarriage – specifically, how much clearance exists between the ground and your vehicle. Try to go over something too big and your expensive SUV will cark it before you’ve gotten half way to the back of beyond.
Be aware of what your brakes can do as well. In slippery conditions, even a slight incline can be a major obstacle. Knowing if your brakes are anti-lock and what traction control you have is imperative to understanding what your four-wheel drive vehicle can do.
When you have to tackle inclines, it’s important that you get used to the idea of two-footed driving. This means that even as you’re accelerating the car to make that climb, you’re stepping on the brake to control any slide. Slow and steady is the best method to take. It preserves the environment and ensures that you won’t be sliding your way back to the bottom of the hill.
Once you’ve made it to the top, remember that the descent could be just as full of unexpected surprises as the ascent. If the hill’s slippery, this is even more important. Align your four-wheel drive with the trail. Go slowly. Keep your foot off the brake pedal. If you’re braking constantly, they might lock up and send you careering wildly to the bottom of the hill.
Now, keep in mind that different off-road situations will require different approaches and angles. The most important are approach angles, breakover angles, departure angles, and roll-over angles. In order to successfully cross an obstacle or navigate a tilted trail, you have to angle the 4WD accordingly.
The approach angle is the angle that extends from the leading edge of your front tyre to the lowest point of the bumper. The first few times you approach an obstacle, stop and get out. Take your time judging the angle to determine if your bumper will hit the obstacle before your tyre clears it.
Breakover angles are the steepest obstacles over which you can drive without scraping the undercarriage. Figuring out the breakover angle can be a little tricky, and the easiest way is to draw it. Geometry will actually be useful here – see, your maths teacher wasn’t lying. Draw your vehicle to scale (just the outline of the tyres and the undercarriage). The bottoms of the tyres are the first two points of the triangle. The lowest point of the undercarriage is the third point. The lower of the two angles is the maximum angle you can drive over without scraping the undercarriage. Once you have this basic visual in your head, you can successfully estimate obstacle heights relative to your off-roader.
The departure angle is similar to the approach angle, but it’s figured by estimating the leading edge of the rear tyre to the lowest point on the rear bumper. This is the maximum clearance you have coming off of an obstacle.
The roll-over angle is one calculation that’s best left to the engineers. Your 4×4 SUV comes with instructions detailing the maximum side slope at which your AWD vehicle can maneuver without rolling over. Don’t take a chance with this. Check your vehicle’s safety standards.
Once you understand these angles and the basics of tackling hills, you’re ready to attempt your first off-road experiences. However, it’s important to remember that these are just the basics. Don’t tackle obstacles that you are unsure of, and seek out instruction to take your off-road driving to the next level.