DIESEL ENGINE

Hawke's Bay Tribune, Volume XXV, Issue 148, 8 June 1935, Page 13

DIESEL ENGINE

Tests of Economy Recently an eight-wheeled cornmercial vehicle weighing, with its load, 21 tons 19Jcwt, and running under the official observation of the Royal Automobile Club, covered 680 J miles at an average speed of 16.7 m.p.h., and with a fuel consumption of 9.64 m.p.g. The owner of a private car weighing, say, one ton would not be at all pleased if his mileage per gallon of petrol were no more than 9J; as a mattter of fact it is probably about 30. In other words, he moves one ton for 30 miles at an expenditure of one gallon of fuel; disregarding any weight of passengers, his ‘‘ton mileage” is 30. If we assume that he has three passengers with him in the car, that its weight so laden is 25 cwt, and that he can still get 30 m.p.g., we find that he can carry 25cwt. for 30 miles on one gallon of fuel, and that his ton mileage per gallon is 37J. Compare thia last-mentioned figure with the ton mileage of the commercial vehicle referred to It is no less than 211.9. The performance is equivalent to that of a private car weighing, with passengers, one ton and travelling more than 211 m.p.g. This is not, of course, quite a fair comparison, for the amazing ton mileage figure is greatly contributed to by ths heavy weight of the load, which was, in fact, .14 tons Djewt. The achievement of the 22-tonner is, however, well worthy of mention, because it was made possible by the use of a Diesel-type engine running on a fuel which could not be employed satisfactorily in a normal internal-combus-tion engine. There are many difficulties in the way of adapting the, Diesel, or ‘‘compression ignition,” engine for use in a private car, but the advantages of such adaptation is manifest. The new Diesel engine—the pattern used during the Tt.A.C. test —appears to possess particular interest for private car manufacturers.

Hitherto the comparatively poor flexibility of the Diesel'engine and the difficulty of designing fuel injection pumps capable of supplying correctly the minute amounts of fuel required for each explosion stroke in a small power unit have been serious problems. In addition, the weight of the Diesel and its cost have been awkward factors. However, in due course, Solutions will, doubtless, be found, and, the compression ignition engine for private cars will com*.