low range (English, Русский)

Low range gear (4L) is for creeping along at slow speeds. It reduces the strain on your vehicle, just remember to stay below 25mph in low range. While it does not provide more traction, it does provide 2-3 times more torque at about 1/2 or 1/3 of the speeds in high range. Low range gear ratios are approximately half that of high range.

Use low range 4WD:

• on wet, slippery surfaces
• passing through sandy areas
• on rough trails
• through shallow water
• rock-climbing
• climbing steep hills
• through mud
• descending steep hills

Tip: Engage low-range 4WD before you need it.

Source: about.com