Whether out in the country or cruising the freeway, a 4WD SUV can be a necessity. Although technically a passenger vehicle, it is also a tool, thus the word “utility” as in “sport utility vehicle”. Like any new tool, a 4WD SUV will take some time to master, and the rules are different for both on and off road use; instructions must be followed for optimum performance – and fun!
Four wheel drive SUV’s generally have three drive train settings: auto (2WD or “auto” on the selector), four high (4H on the selector), and four low (4L on the selector). These settings simply tell the driver how many wheels are driving the vehicle at any given time, and how much power is being transferred to those wheels. For instance, when the vehicle is in 2WD, only two wheels are driving the vehicle, just like a standard car. When the setting is changed to 4H, so it the same as a 4×4 vehicle, more power is transferred to the wheels, and it can be driven at highway speeds. 4L is known as the “granny gear”; all four wheels are driving the vehicle with maximum power, and it can only be driven very slowly.
Generally speaking, a 4WD SUV spends most of its time on the street in 2WD mode. In the name of fuel efficiency, the vehicle should ideally be left in 2WD on dry, paved roads. Of course, many times road conditions are less than ideal. Switching to 4H should be considered when the road is slippery, usually in snow or ice, and can usually be done while the vehicle is in motion.
The 4L mode is rarely used on paved roads, but the need does occasionally arise. Since 4L can’t be selected while driving, the driver must stop the vehicle and shift into either park or neutral, depending on model. The vehicle can then be placed into 4L. The driver must wait for the transfer case to engage, in which a “clunk” can usually be felt or heard, before driving. To ensure the vehicle is in 4L, a test called the “crab-walk” can confirm engagement. This is done by putting the vehicle in gear, turning the steering wheel all the way to the right or left, and slowly accelerating. If the vehicle doesn’t drive smoothly or skips, 4L is engaged.
Unlike on pavement, 4H may be needed on dry as well as wet ground. The 4×4 vehicle should be kept in 2WD if the trail is reasonably smooth and flat. Rough or steeper trails may require the use of 4H. The 4H mode should be engaged before attempting to climb a moderately steep trail with loose material on the surface.
The general rule for driving a 4WD on an off road trail that’s muddy or very steep is to put the vehicle in 4L before attempting to navigate the road. Once on the trail, the best way not to get stuck is to use the vehicle’s momentum to get through the rough spots; stopping in the mud is a surefire way to ruin a trip before it even gets started. Another rule of thumb is not to drive the 4WD through mud or water that is deeper than half the height of the 4×4 vehicle’s wheel. Wet or dry, when driving off road, slow and steady always wins the race.
Driving a 4WD SUV is different than driving a car or a truck. One might say it’s the best of both worlds. Most who own one agree.