Honesty and Horsepower

A motor journal can check accurately on the performance of cars submitted to it for road-test by using stop-watches, a fifth-wheel, electric speedometer, fuel flow meters, and so on. But it is completely at the mercy of the manufacturers when it comes to publishing brake horsepower figures, because it is scarcely feasible to remove the engine and place it on a dynamometer, even assuming a motor journal has one of these useful pieces of apparatus along with its stop-watches, fifth-wheel, electric speedometer, etc. The position is further confused because b.h.p. is quoted by some makers as a net figure, by others as the gross output, and because it can be expressed in terms of British, D.I.N. (German) or S.A.E. (American) assessments, the components with which the engine is tested varying in each case. Furthermore, it has never been revealed how makers obtain their catalogue b.h.p. figures—on an average of many readings taken with many engines or the best figure available when the publicity department has a catalogue to compile.

It is on account of these variables, and not entirely due to pomposity, that Rolls-Royce, when asked what power their car engines develop, reply “sufficient”.

Consequently, we were interested to see that in its May issue Australian Motor Sports & Automobiles has made some attempt to investigate this matter and to decide whether dishonesty enters into it. What it did was to test 37 cars on Australian Motor’s Perfectune chassis (roller) dynamometer, after consulting with Melbourne University’s engineering department about the best way to approach the problem. The snag, as we see it, is that power losses in the transmission, etc., vary sufficiently in different makes of car to distort the figures when related to engine especially some of the cars tested had automatic transmission and others manual-change gearboxes.

Nevertheless, it seems worth quoting the findings; we refrain from publishing the resultant graph and table, which would be unfair to the journal concerned. Summing up, Pat Hayes, who wrote the article, says: “It’s obvious that no manufacturer is telling any big lies and equally obvious that the much-maligned Japanese h.p. figures are the equal of their Western counterparts. The graph and figures indicate that Continental horses are bigger than British horses and that Ford’s horses are bigger than those of GM-H and Chrysler.”

Incidentally, another aspect of this Australian article which was interesting to us was the remark: “The Volvo 144S is disappointing—as was the test car.” So we were not alone in finding this to be a disappointing car, and to this we would draw the attention of those enthusiasts for this make who think our report on the Volvo 1445 was unfair.—W. B.