Most 4WD systems offer drivers the option of shifting between the 4WD high or 4WD low range, according to Edmunds. The default setting is the high range. When to use high range vs. low range depends on driving conditions.

4WD High

Popular Mechanics notes high range is for higher speeds and less traction than 4WD low. Edmunds recommends using 4WD high range on dirt or paved roads that are snowy, slick or icy

4WD Low

Edmunds says 4WD low range is for off-roading conditions, like deep sand, where you need serious traction. Unlike 4WD high, adds Motor Authority, the low setting turns the wheels slowly but gives you more torque on less forgiving terrain.