After pointing out that the publication of articles in the trade and technical journals, to the effect that very considerable weight-reductions in motor-truck construction with consequent savings in gasoline and tires are possible, works an injustice to the motor-truck industry and is misleading, the author outlines some of the reasons why such weight-reductions are very difficult to effect, as well as the possibilities of standardizing axle details. The use of aluminum to effect weight-reduction is commented upon and the various advantages claimed for metal wheels are mentioned. In the latter connection the author points out that, while these claims may be true, they are unsupported by reliable data.
The greater part of the paper is devoted to an account of a series of tests conducted by a large coal company to determine the relative merits of wood and metal wheels on its trucks. Four trucks, each equipped with wood and metal wheels on diagonal corners so as to secure, as far as possible, an equalization of conditions were employed. The tests lasted over a year, and at their conclusion it was found that the average wear of the tires mounted on metal wheels was about 13 per cent greater than that of tires mounted on wood wheels.
The question of unsprung weight is discussed, as is the importance of reducing chassis and body weights to a minimum, but it is pointed out that a reduction in these weights does not necessarily mean a resultant saving in the gasoline consumption or the tire expense. Lubrication of the various parts of a motor-truck chassis also receives attention, the annual cost of truck repairs due to poor lubrication of the chassis being given as from $15,000,000 to $20,000,000, in addition to which there is a loss of earnings while the trucks are being repaired of from $30,000,000 to $35,000,000. The superiority of oil over grease as a chassis lubricant is emphasized.
In conclusion it is pointed out that the next few years will see bitter competition in motor-truck service and that refinement of detail and simplification of operating features will be emphasized. The need for the unexperienced buyer to secure expert advice regarding the design of the vehicles offered him is stressed, it being stated that this practice would clarify the situation for both the buyer and the seller.