FOUR WHEEL DRIVE

Putaruru Press, Volume IV, Issue 127, 8 April 1926, Page 7

FOUR WHEEL DRIVE

SOME ADVANTAGES. - Study for Engineers. j Now that braking with all four wheels has become an accepted practice, automobile engineers, in their incessant search for things new and useful, are beginning to consider the possibility of going still further and applying the driving power through all four wheels instead of through the rear ones only (says an American paper). Four-wheel driving has long been a recognised method of commercial vehicle propulsion, its application to army trucks having rather recently given it a great impetus and a high degree of development, and now it is being argued that if it is a good thing for trucks, why should it not be advantageous for passenger cars'? Every motorist has some time found himself with his car 1 ‘stuck” in the sand, mud or snow, and has realised that if his engine power could be positively applied to front, as well as rear wheels, his car would in all probability pull through the bad going without difficulty. Now that automobile transportation is depended upon in all seasons by so large a fraction of the public, it must be made as nearly as possible proof against interruption by even the most adverse road conditions

and four-wheel driving seems the obvious solution. With all four wheels driving, the front part of the load as well as its rear portion is pulled and not pushed over the road irregularities, a saving in power being effected through elimi- 1 nation of the inefficient pushing action f of conventional front wheels, which merely support and guide. All wheels I roll under their own power. , With correct design, there would bo . no differential action that could cause one wheel to slip and prevent tractive effort being transmitted to the road. A single transmission brake ‘ would apply its retarding effect to all ] four wheels simultaneously, as they are all mechanically connected. Skidding (tendency would be reduced for the reason that all wheels would be positively rotated and side-slip occurs with wheels that have stopped turning, not with those that are rolling normally. Each of the four final drives to the wheels would be under much loss severe stresses than the two final drives of the conventional car, especially since the entire propulsive force would be reduced by the more advantageous api pliction of power to the road. Tyre- i ! wear of front and rear wheels would be equalised and its total amount reduced.