EMPHASIS ON ECONOMY A COMPARISON OF PERFORMANCE OF THE SMALL CAR OF TO-DAY
AFIAT ” 500 ” recently completed an R.A.C. observed fuel-consumption test, in the course of which it was driven from the Fiat factory at Wembley to Newcastle-on-Tyne and back, a distance of 571} miles, the fuel consumption working out at the remarkable figure of 63.97 m.p.g. The standard closed 570 c.c. car was used, it carried two adults, ran on No. 1 petrol and did a running average of 32.2 m.p.h.—the R.A.C. observer probably insisted on the speed being kept in the region of 80 m.p.h. average so as not to offend the nonautobahn-minded British public who might see the report of the test, because a good driver would be more likely to average about 35 to 37 m.p.h. on a car of the baby Fiat’s qualities over this route and apparently speed was not specially restricted to humour economy. Certainly the result of this test gives one furiously to think. Here we have a 570 c.c. two-seater car averaging 82 m.p.h. and 64 m.p.g. for 570 miles of British going. As an eminent authority estimated last month that about 80 per cent. of new car buyers at the present time buy cheap cars of under 12 h.p., even MOTOR SPORT may be excused for devoting a little of its ,space to economical performance. The question arises, what is the smallest possible engine that will give us 55 m.p.h. cruising, from which a useful 35 to 40 m.p.h. average on mainroad going will follow ?—although the maximum will probably be around 60 m.p.h., because it is a characteristic of the baby car to cruise indefinitely almost flat-out. Generally speaking, the smaller the engine, the greater the economy of operation. For years one of the smallest units in serious service has been the Austin Seven of 747 c.c. The later examples give something of the speedperformance craved above and seldom less than 40, sometimes as much as 50 m.p.g. of No. 1 fuel, or an average m.p.g. of 45. Other really small engines have been the 719 c.c. Peugeot of 51 X 88 mm.—not the pre-war ” Baby” or later ” Quad” but the post-war 7-12 h.p. of which few are still in serious service ; the Singer Junior of 56 x86 mm. (848 c.c.) ; the earlier M.G. Midgets, the Morris Minor of 57 x 83 mm. (847 c.c.) ; the 7.5 h.p. Citroen, the 600 c.c. Jawa of Czechoslovian origin (said to give 19.5 b.h.p. at 3,500 r.p.m.) and the 684 c.c. two-stroke D.K.W. Lots of other cars of 8 h.p. have been marketed, but they have had long-stroke engines, making their capacity considerably higher. The present Austin Eight, of 900 c.c., is a notable example, likewise the Austin Big Seven, the old Fiat Eight of 990 c.c., the vintage Gwynne Eight, which had a capacity of over 1,000 c.c. and the famous flat-twin Jowett of 7.35 h.p. but in size as large as 946 c.c. The modern tendency seems towards small bore, long-stroke eights, as witness the new Standard Eight; which actually has a capacity of over a litre. Incidentally, the first Austin Seven had an engine of 698 c.c., but it was increased to 747 c.c. for
racing purposes. Apart from the s.v. Morris Minor the Austin Seven was about the smallest car to adopt a fourspeed gearbox some years ago. Most of the two-cylinder ” eights ” of earlier times that you may think up will be found to have a capacity in the region of 900 c.c. or more—the later Rover flat-twins, so popular in their day, were of 85 x100
ram. and rated as 8.8 h.p. Modern motorists will not tolerate the roughness and noise of a twin, albeit we have frequently referred to the distinct possibilities of Such an engine for a very potent, notably economical, enthusiasts’ car. So far as the genuinely small fourcylinder engines aforementioned are concerned, nearly all would give around 40 m.p.g. and cruise a four-seater closed car at 40 to 45 m.p.h., but we believe the Austin Seven to have been the most economical of them all, Now Fiats have shown us 64 m.p.g. with a car which cruises at nearer 50 than 45 m.p.h. On our own test of a Type 500 Fiat, we found the cruising speed to be 50 m.p.h. and the fuel consumption about 45 m.p.g. and seem to remember averaging 37 m.p.h. and 47 m.p.g. on a later run, up to Donington, with a private owner in one of these cars. When we tried the 684 c.c. D.K.W. in February, 1938, we reported that it cruised comfortably at 40 m.p.h., and averaged 38 m.p.g. Encouraged by these figures, we are going to suggest that it should be possible to produce a car that would give really useful performance with extreme economy. In fact, a sort ox ” 5/55″ motor-car, by which we imply a cruising speed of 55 m.p.h. and a fuel consumption of 55 m.p.g. A cruising speed of 55 m.p.h. would enable one to average about 40 m.p.h. almost anywhere, given reasonable road-clinging and braking—the average, present day baby hums along at 45 and averages 30 to 35 m.p.h. Fifty-five m.p.g. would be true economy. Cer tainly, it may be argued that as a good 40 m.p.g. baby can be had secondhand for .4;70 and as our ” 55/55 ” wagen will cost at least 4120, it will take some eight years, covering 10,000 miles a year, before the extra cost of the new car will be washed out on its comparative fuel economy. Actually, of course, only a secondhand dealer in soiled babies would argue thus, because there is a distinct market for both new and used. vehicles— witness the number of Fiat ” 500s ” and D.K.W.s and Austin Big Sevens and Austin Eights on the road, in spite of the flood of late-type under 850 c.c. secondhand stuff for sale at attractive prices. On the other hand, the new car buyer would save some £27 in four years, the likely period of ownership, or over £50 if he did a really big annual mileage, on saving in fuel bills and taxation alone, apart from superior performance. So someone might do well to start experimenting with a British ” Volkeswagen,” to meet Italian and German competition— especially now the small Austin has swollen some 150 c.c. A 500 c.c. unit might do the job, although o.h. valves and very careful construction would probably be desirable, which puts up first cost. High revs. are not a crime now that racing has taught us how to build reliable fast-revving units, and modern insulating and sound-proofing methods are available. In any case, we believe the proposed-performance and economy might be achieved with quite a simple 650 c.c. unit, if the designer knew his stuff, and certainly the bore might be limited so as to command the lowest annual taxation rate—L4 10s, per annum. To argue that if a man can find £120 for a motor a few extra fivers now and then cannot worry him does not hold water, when you recollect that the majority of our ” 55/55-wagens ” would be purchased under a highly favourable hire-purchase system (much as we personally disapprove), or that ready-cash, essential for buying fuel away from home, is not always as easy to come by at the end of the week or money as it is at the beginning. Reverting to technical considerations, which we hope may be less depressing than the financial, we do not advocate supercharging, because of
its adverse affect on fuel consumption— we know of a blown example of the Fiat ” 900 ” which gives some truly amazing acceleration figures and goes the astounding pace of 74 m.p.h., but its fuel consumption is about 35 to 37 m.p.g.; still very excellent but not in keeping with the Performance-cum-Economy car we have in mind. But we believe the necessary qualities could be got uublown. Even if the idea of 55 m.p.h. cruising at 55 m.p.g. proves impossible someone might give us a 500 c.c. engine of really sound design, which could give a performance akin to that of the wonderful little Fiat “500 “—which, as we have said, means a 35 to 37 in.p.h. average almost anywhere—while giving something like 60 to 65 m.p.g. of fuel under allround, day-in, day-out conditions, and commanding the kt 10s. tax. We hope someone will experiment with wide-gap ignition and weak mixtures on the little Fiat engine, and tell us how this car’s 50 m.p.h. cruising164 m.p.g. consuinption is affected. Such modification might well make possible the existing 40 to 45 m.p.h.. cruising of the Austin Seven, with a regular fuel consumption of 60 or more m.p.g.—the Vauxhall engineers get 40 m.p.g. from the very snappy Vauxhall Ten by this method. We believe there would be scope for a British economy car which is both more economical and faster about the place than any existing
small car. But wouldn’t it be terrible if we evolved the engine, only to find that the thing still only averaged 80 m.p.h. because of its road-holding and braking and steering . . . ? Meanwhile, congratulations to Fiat for proving that a car which we know can cling to the road and cruise at 50 on 570 c.c. will do 64 m.p.g.of fuel on a long, main-road journey.