The German word “Gelände” refers to terrain or country away from ordinary roads.
In some transmission systems, a G gear was associated with low-speed terrain operation.
That is why the letter can sometimes appear instead of the familiar numbered-gear convention.
Rather than indicating a normal fifth or sixth gear, it identifies a special ratio intended for difficult conditions.
It is essentially a signal that says:
This is the gear for slow, demanding terrain.
This terminology is one reason the letter can appear unusual to drivers who have only operated conventional passenger vehicles.
It Is Not a “Go Faster” Gear
One of the easiest mistakes would be to assume that a mysterious letter on a gear selector represents an additional high-speed gear.
That is generally the opposite of what a crawler gear is designed to do.
A very low gear is about torque and control, not speed.
The lower the gearing, the more the transmission multiplies engine torque at the wheels while reducing vehicle speed for a given engine RPM.