The Oil Engine Still Scores
Page 42
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Despite the Additional Heavy Tax on Oil Fuel Efficient Units Can Give Great Economy By W. H. GODDARD, A. M. Mech. E.
A SEVERE shock has been given ri to us all by the Chancellor of the Exchequer. We knew that it had to come at some time, but it was not expected all at once. It is indeed a serious matter suddenly to increase the tax on oil fuel by no less than 7d. a gallon—in other words, 700 per cent—but the inherent and extraordinary advantages of the oil engine in road transport are such that it has come to stay, and will gradually oust the petrol engine from its present predominant position.
When we come carefully to examine all the points and take into consideration the elimination of the extra Road Fund tax imposed last year, the preliminary shock is considerably softened, and it is quite clear that the oil engine is still a fine investment.
Take, for example, the case of the double-deck bus. For a•48-56-seater the extra Road Fund tax on this is £61 12s. It was not generally realized that on an annual mileage of 50,000, this represents 3.54d. per gallon of fuel, so that, actually, instead of the oil costing 5d. per gallon it costs 8.54d., if the tax be converted into a charge per gallon. Actually, with such a vehicle, the new tax means practically 4d. more per mile.
Now, the figures in August will be
as follow :—Petrol bus, fuel cost for 50,000 miles, £430; oil-engincd bus, fuel cost for 50,000 miles, £208— advantage to the oil engine, £222. From this, however, we must deduct the depreciation and interest on the extra £250-£300 for the purchase of the oiler, say £60 per annum, leaving a net gain of £162 per annum.
Assuming depreciation over a period of five years, we can say that in this period a big oil-engined bus will show a clear gain of 2810 over the petrol type, and when this is taken into consideration over a large fleet of vehicles, such as the 600 of London Transport, the tremendous advantage of the oil-engined vehicle, even with the additional tax, will be realized.
What is now most evident is that the impost will put a premium on high-class engines, i.e., those with the best thermal efficiency or fuel consumption. A difference of 1 m.p.g. was not of great importance with fuel at 5d. per gallon, but at Is. it is of considerable moment.
In The Commercial Motor dated April 19 you say " . . but to
operate efficiently, the oil engine requires considerably more lubricating oil. . . ." Whilst it is agreed that some engines do use a great deal of oil, there are others which consume less than a petrol engine. In proof of this, we can take the figures of an important Yorkshire company which operates 10 oil-engined buses. Some of the vehicles were new, others were converted from petrol. The mileages given are those which each vehicle has run since delivery. Until recently, the oil was changed only every 10.000 miles; now it is changed every 6,000. The single-deck Bristol buses have Gardner 41,W units. The lowest mileage run is 34,218; the average figure for lubricating oil is 2.534 m.p.g. Another which has run 39,361 miles gives 4,362 m.p.g., and a third, the mileage of which is 102.856, still averages 2.742 m.p.g. A Guy double-decker with a:Gardner 61,W engine has run 43,847 miles and gives 1,970 m.p.g. A Leyland Titan with a similar engine has 91.159 miles to its credit and gives 1,823 m.p.g. Over the whole fleet, the mileage is 542,650, and the average mileage per gallon of lubricant, 2,383.
A new modern petrol bus usually starts by giving about 1,200-1,400 m.p.g., but this gradually falls away, and at 100,000 miles the figure varies between 300-500 m.p.g.