Four Wheel Drive Concepts
   Four Wheel Drive Types
   Petrol vs. Diesel
   High & Low Range Gears
   High & Low Range Gears
   Suspension Types
   Vehicle Recovery Points
Offroad Driving Techniques
Vehicle Recovery Techniques
High and Low Range
Gearing lets your car move forward and backwards, and, by selecting a higher gear, lets your axles (and consequently your vehicle) move faster than engine rpms. In four wheel drive, however, gearing is also used to help you over difficult terrain such as steep hills.
High Range
High range gears are the gears normally found in any motor vehicle. These gears are used for day-to-day driving on tarmac, motor ways and in the city. High range gearing uses a high gear ratio (3:1 in the figure at right) to spin the axle with speed, but a lesser amount of torque.   High range gearing
Low Range
With low range gearing, the opposite holds true - the axle spins at a much lower rpm, but with a huge amount of torque (1:3 in the firgure at right). The vehicle therefore moves substantially slower, but with much more power. When driving off-road this is beneficial for a number of reasons. For example, when driving up a steep hill a car equipped with high range, or "normal" gears, would lack the power to make it to the top and, in all likelyhood, stall. However, a vehicle equipped with low range gears would simply drive on up because of the added torque.   Low range gearing
Ascending a steep slope   Many of today's leisure four wheel drives (such as the Land Rover Freelander and Toyota RAV4) do not come equipped with low range gearing, and consequently are not very capable performers in the really rough stuff. To reach the top of the hill depicted in the picture at left, a vehicle not equipped with low range would require a huge amount of momentum. Excessive momentum in turn can cause you to damage your vehicle and possibly injure yourself. So think about how you intend using your vehicle before making a purchasing decision.