The various modes of four-wheel drive dictate different safe driving speeds in a range of conditions. High-range allows for traveling at normal speeds, while low-range requires lower traveling speeds of 40 mph or less. Four-wheel drive is designed to create extra traction so a vehicle remains in control during difficult driving conditions such as snow, ice, sand, mud or slick pavement.
While using a four-wheel drive system driving on flat, dry surfaces is not recommended because of the potential damage it could cause to the drive train, it is extremely helpful at making a dangerous driving situation safer.
High-range four-wheel drive is designed to handle moderately difficult driving conditions such as snow, ice or flat surfaces with loose covering. This allows for traveling at normal highway speeds safely. For deep mud, snow, sand and other highly dangerous situations, low-range four-wheel drive is more appropriate. When using this system, it is important to drive at lower speeds.
Automatic four-wheel drive switches from two-wheel drive to four-wheel drive whenever the vehicle begins to slip. Regardless of the conditions that cause the four-wheel drive to kick in, it is important to drive at a slow enough speed that the vehicle can be brought to a complete stop quickly and easily.