WHEELBASE CLASSIFICATION

Hawera Star, Volume LI, 20 February 1932, Page 12

WHEELBASE CLASSIFICATION

GUIDE TO CAR SIZE. DIMENSIONS ENUMERATED Owing to the British method of describing cars by their somewhat artificial horse-power rating, many motorists tend to lose sight of the fact that the wheelbase is by far the most useful guide to the size, weight, and body space of an automobile. It is a pity lhat this invaluable dimension should be neglected, particularly in view of the fact that the modern tendency is to provide a choice of engines in chassis which otherwise are well-nigh identical.

For example, we may take a number of medium-sized cars, all with a wheelbase of between 9ft 6in and lCft. the ratings of which may vary, according to engine size, between limits as far apart as 14h.p. and 24h.p. The body and the general size of the car is practically the same in each case, yet people automatically tend to think of a 24h.p. car as necessarily being much bigger than a 14h.p. car. Naturally the rating is useful as giving an idea of the size and power of the engine and as showing the tax which is payable in Britain, but it should he limited to these purposes and should not be taken as a guide to car dimensions.

Another advantage of getting to know the wheelbase is that it gives a good idea, of the overall length of the car, which is often very important when garage accommodation is limited. Similarly, although to a lesser degree, the track is a most useful dimension to keep in mind, as it is a measure of the overall width and also gives an idea of the internal dimensions of the coachwork. The wheelbase and track are invariably stated in the manufacturers’ specifications, and the following average figures will .show how they vary in the car types which are most popular nowadays. Commencing with the “baby” cars, which provide full scale seating lor two people and emergency seating for additional persons, it will be found that wheelbases vary between 6l't 3in and 7ft,.while the track is usually 3Jfi or slightly less. These dimensions inthe minimum size to which a motor-car can usefully be built. Next, comes the new class of economy car in which full-scale four-seater coachwork is ingeniously fitted to a chassis o! small dimensions, the minimum wheelbase employed being 7ft 6in and the maximum nearly Bft. Here, again, the track is usually limited to 34ft. Proceeding in order of size, we come to a class which embraces the 10 li.p. four-cylinder models and small sixcylinder cars rated at about l'2h.p. In each case, the body-work is of much the same size, providing adequate icom for four people but capable of carrying five at a pinch. The wheelbases employed range from Bft to Oft and the track is usually about 4ft. Naturally. :i six-cvlincler engine is a few inches longer than the four-cylinder type, so that for the same body space the wheelbase of a “six” must be proportionately increased. Before going farther we may mention that the overall length of the cars we have described are usually found to he from 3ft to 44ft longer than the wheelbase, while the overall width may be taken as nearly Ift greater than the track in almost all cases. We now come to a car class which provides somewhat roomier body-work .suitable for carrying three people in reasonable comfort on the rear seat. Here a. great variety of engine powers is available ranging between limits of about loli.p. and 2oh.p. The highpowered examples are mostly of transAtlantic origin, but there is a growing number of British cars rated as high ns 20h.p., which appeal to those who appreciate a power-weight ratio • sufficiently to pay a heavier tax for this luxury. The wheelbase of this class of vehicle varies between 94ft and 10ft. and the track is usually the standard dimension of 4ft Sin; there arc, however, examples of the use of slightly narrower tracks”.

The overall length may he anythin" from 4ft to 5-Jft longer than the wheelbase, according to the space occupied hv projections, such as bumpers, luggage grids, and spare wheels. The width, as in .smaller cars, is usually about Ift greater than the track. Turning to larger cars usually rated at over 24h.p., we find that the wheelbases range from 10ft up to something in the neighbourhood of 13ft for the very longest and most costly types. Generally speaking, to carry sevenseater coachwork with proper space for occasional seats a wheelbase not shorter than 10ft Gin is necessary. In this class a 4ft Bin track was at one time universal, but nowadays, in order to provide still wider bodies, many makers are using tracks of sft, nr even greater dimensions. The overall lengths of these ears are usually between 4 i ft and s}ft greater than the wheelbases, and the widths are from Ift to l.jft greater than the track. In conclusion, it may be mentioned that manufacturers try to use a moderate wheelbase and trade for the reason that by doing so weight and cost are reduced.