4WD High Range and Driving Conditions
Drive To The Road Conditions. Be in the correct place on the road, have the right speed for the conditions and the correct gear for that speed. (Consider 4H for driving on unsealed roads. It gives you far more control over the vehicle especially on corners. But remember to deselect before going back onto a tarmac road.)
Avoid Any Sudden Changes In Steering. Making sudden changes in steering can cause your vehicle to go into a skid on an unsealed road.
Expect The Unexpected. Be prepared for any eventuality. And have a “what if” plan made for each.
Be Alert and Focused. You should be able to remain calm and focused at all times when in charge of a motor vehicle. If you can’t you should stop and rest.
Remember, when driving on unsealed roads, even if the road is good and dry it still has an unstable road surface. Just look in your rear view mirror and see the road surface coming up behind you as a dust cloud.
You have 50% less grip with the road surface as you would on a tarmac road. Therefore, you are twice as likely to loose control of your vehicle and it will take you double the distance to stop in an emergency. It makes sense then to keep your speed down. Stay below 80 KPH whatever the conditions.
4WD High…how is that used..!!
Technically we should use 4WD high range whenever the vehicle is on the surface that can allow one wheel to slip. However when you find yourself traveling beyond 50 km/hr you start to enter a gray area. Evidence suggests that the majority of serious 4WD accidents occur on gravel roads. Why?
Gravel roads vary; even the same stretch can change surface friction, and roughness within days. That added with the extra size and height of a 4WD and the function of the drive train can cause problems with control.
Driving your 4WD in 2WD mode on gravel requires techniques that allow for setting up and planning the control of the vehicle. Positioning, braking and cornering with a heavy vehicle has to be thought out before the corner due to the horizontal forces (and momentum) that act on the vehicle on the loose surface.
Driving in 4WD on the same surface at slower speeds offers more control . The vehicle will brake in a shorter distance but will not be able to be steered aggressively when cornering. If cornering at speed in 4WD , above 50km, the wheels tend to break away from the surface. This is due to both axles being feed the same power and the front axle travelling further than the rear at a corner. Here an AWD system works better when the front and read drive shafts can be driven at different speeds without the two fighting each other.
The right selection of the drive train (2WD,4WD,AWD) requires as much understanding as the correct use of wheel printing and terrain appreciation so be very careful when travelling…