Four Wheel Drive
Four Wheel Drive (Automobile) The two main traction problems associated with a two-wheel drive (4 x 2) vehicle are loss of traction during cross-country operation and loss of adhesion during acceleration. To provide a solution to these problems, Harry Ferguson, the inventor of the light weight tractor, was the first person to understand the importance of "all-wheel drive". In 1954 he patented the "Ferguson Formula" (FF), which was used on the Jensen car in the early 1960s. In a four-wheel drive (4 x 4) vehicle (four by four vehicles), the drive is transmitted to all the four wheels. The intended use of the vehicle governs the type of 4 x 4 drive system that is offered by the manufactures. Some vehicles are designed to work efficiently both on and off the highway. These vehicles use two-wheel drive on 'hard' surfaces and restrict the use of four-wheel drive for cross-country operation where it is likely to encounter muddy surfaces leading to loss of traction