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KEEPING COSTS
Page 106
Page 107
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to the MINIMUM
Consideration of the Importance of the Various Items of Cost and the Direction in which Efforts to Reduce them Should be Made
THE running costs of commercial motors of the same type and capacity sometimes differ considerably, even when the vehicles are engaged on similar tasks. They differ even more so, of course, when the work varies in its nature and when the road conditions alter. Given equivalent conditions, however, there seems to be no obvious reason why the cost of operation should not be the same for all machines of the same size. The fact that it is not provides food for thought. Generally, the personal element is adduced as the principal cause.
Now, attributing the variation to the effect of the personal element is merely a highfalutin way of stating that some drivers obtain better results from their vehicles than do others. Like most generalities, it is only a half-truth.
First of all, it should be recognized that something at least depends on maintenance and something, too, on the individual vehicle, even in a fleet of machines which are all of the same make and size. But, when all is said and done, the main factor in economy of operating cost is the attention that the vehicles receive at the hands of those who are responsible for their upkeep. .
The answer to the question: "How can costs be kept to the minimum? " can be given in two words : "by care." It is necessary to simplify the meaning of the term only by indicating how it should be interpreted in respect of its application to the various items of cost, so that each may have its fair share of attention and, more particularly, perhaps, so that none may be missed.
A First-class Vehicle Essential.
As a preliminary it may be stated—and, I think, without fear of contradietion—that the first essential is the selection of a vehicle of first-class make with a first-class guarantee behind it. In that way we ensure a fair start.
Even without that favourable commencement it is still possible, by attention to details, to reduce the' incidence of most of the items of cost, and as a preliminary it is advisable to appreciate the relative importance of each of them. Most users think of cost in terms of petrol and oil. Many go no farther, but of those who do the majority merely adds " tyres " and is content with those three, as against the 10 items which appear so regularly in our Tables
of Operating Costs and which have all to be met, &mile:. or later, in the life of every motor vehicle.
Now, fuel and tyre costs are undoubtedly important items in the cost of operation. Their relative importance does, however, vary considerably in accordance with the use which is made of the vehicle. A brief reference to Fig. 1, which shows bow these two items of cost vary in proportion to the total as the weekly mileage increases, is illuminating on this subject. The height of the curve at any point is an indication of the percentage of the total cost that is represented by fuel or tyres, as the case may be. It is of interest to note how rapidly the curve rises. At 70 miles per week, for example, the fuel cost is about 20 per cent, of the total, but at 80 miles per week it is practically SO per cent. In the same way the tyre cost proportionately increases, but is less than that of fuel.
Explaining the Graphs.
In Fig. 2 the cost of fuel is plotted in relation to the size of the vehicle and two graphs are shown. One is worked out on the assumption that the vehicle covers 200 miles per week, whilst the other is based on a weekly mileage of 800. The curves indicate that the cost of fuel is of increasing importance as the load capacity of the vehicle becomes larger. The same conditions are present in regard to tyre Costs, as is illustrated in Fig. 3, which shows how the tyre cost per mile varies with the load' capacity. In this Fig. also two curves appear, one depicting the conditions when the weekly mileage is 300 and the other when it is 800.
In Fig. 4 a diagram of a different type is utilized to show the relative importance, one to the others, of all the five
items of running cost. That of fuel is seen to be the greatest, whilst tyres, maintenance and tfepreciation are approximately equal. The cost of lubricant is comparatively small. The figures on which this diagram is based are averages relating to all sizes of vehicle. They do not, of course, take any account of the weekly mileage.
Figs. 5 and 6 are the most important, as well as, perhaps, the most interesting. They emphasize plainly, in the first place, the way in which the importance of standing charges diminishes as the weekly mileage increases, and they make it quite clear than one effective way of reducing the cost per mile is to increase the useful weekly mileage of the vehicle concerned.
Wages Should Remain Untouched.
Of the standing charges, no item is capable of any appreciable reduction. The only one which is to any extent variable is that of wages, and that is most emphatically one which should be left alone, or, if altered, may often with wisdom be increased. The correct procedure is to pay good wages so as to attract good drivers and make it worth their while not only to stay, but to do their work well, so that they may retain their jobs. A good driver can effect economies not only in the operating costs of his vehicle—often enough in themselves to offset any increase in his wages—but, by increasing the weekly mileage, may make his wages an insignificant part of the cost of operation, as is clearly indicated in Fig. 6. Indeed, one way to diminish operating costs is to pay good drivers a bonus based on weekly mileage.
Direct Economies on Petrol•Difficult.
Taking now the various items of cost in their order and starting with petrol, it is not often that direct economies are possible. Petrol consumption is more often increased by faults in the chassis and the conditions of use and of driving than by defects in the carburetter itself, of either wear or maladjustment. When the vehicle has covered from 500 miles to 1,000 miles it is worth while to have the carburetter adjusted by the maker or the maker's agent, and after that to leave well alone, unless there be obvious signs of derangement By "leave well alone" I do not mean that the instrument should not be cleaned at regular intervals, but that the adjustment should be left untouched. The condition of the tyres is also an important factor in fuel consumption.
As regards lubricants, ample, but not excessive, lubrication is a good way of diminishing the much more important item of maintenance. Use a good oil, but not necessarily an expensive one. It is often possible to economize in engine oil by refraining from emptying the crankcase too frequently.
Prudent Savings in Lubrication.
A certain amount of judgment must be exercised here, but, in general, unless the vehicle be customarily employed under conditions which involve it in inhaling, through the engine breather and the carburetter, a considerable amount of dust and grit, it is safe to double the periods for oil changement given in the makers' handbooks.
There is considerable room for economy in expenditure on • tyres. The tyre makers' usual figure for maintenance of
fleet-owners' tyres is much less than half that which is given in The Commercial Motor Tables of Operating Costs. Even, therefore, if the savings possible were only those reflected in expenditure on tyres alone, they would justify the maximum of attention. Actually, the condition of the tyres and of the axles and wheels which they support affects every other item of running cost. Tyres which are properly inflated may be said, as a general rule, to absorb less power than do those which are underinflated. Faulty alignment of the axles or wheels, an important factor in the care of tyres, also conduces to increased petrol consumption and to heavy maintenance charges.
Encouraging Cleanliness.
Maintenance costs can be reduced partly by good organization—so that the minor operations are performed when the vehicle and driver would otherwise be idle—and partly by applying the moral implicated in the old saying that "a stitch in time saves nine." Encourage cleanliness of chassis as well as of bodywork and the same automatic recognition of the need for occasional adjustment will occur.
That and fairly regular attention to the recommendations of the maker of the vehicle, as embodied in the instruction book, will go far towards reducing maintenance costs. S.T.R.