5
Cars &
Trucks4WD Low uses gearing to multiply
torque to the wheels, useful for slow
trails or towing a boat out of the water.
But generally, Low is strictly for slow
off-roading, which is why it’s usually
relegated to pickup trucks and SUVs
that have serious off-road pretensions.
A Toyota 4Runner would have it, but
a Highlander wouldn’t. One use case
for this setting: beach driving, where
you want all the torque and traction
you can get. Once in 4WD Low, you
should also lock the rear differential,
usually a switch on the dash with four
tires and a little “x” between the rear
ones. This locks the rear wheels side-
to-side, which can be handy because
if one side loses traction, the opposite
side keeps spinning, powering you for-
ward. (Just don’t use the diff lock on a
corner, because the whole point of a dif-
ferential is to allow your car to make a
smooth turn, with the outside tire turn-
ing faster than the inside.) There are
also a few vehicles with a front differen-
tial lock, but if you bought one of those,
then you probably know how to use it.4WD High locks the front and rear
axles together, which is useful in
only a few situations. For example,
somewhere low-traction, but high-
speed—probably off-road, like a
desert wash. Here, 4WD High tends to
feel more stable, since the truck won’t
want to turn. But most of the time, if
you have both, you’re better off in 4WD
Auto, letting the system send power
forward or back as needed. A friend
used to have a late-’70s Jeep Chero-
kee with 4WD Auto. The only time he
needed to switch it into 4WD High was
when he (successfully) drove through
a pond.
4WD LOW4WD HIGHJOHNWATSON^ (JEEP);COURTESYLANDROVER^ (DEFENDER)