THE MOTOR WORLD.

Otago Daily Times, Issue 19584, 14 September 1925, Page 5

THE MOTOR WORLD.

By ACCELERATOR. (Continued from page 4.) MOTORING IN ENGLAND. THE COST OF SMALL CARS. An account of the cost of motoring England is given in the Spectator by E. T. Brown. Ho says there are serviceable 15 to 20 horse-power cars on the road to-day which can easily be run for 2d a mile or less; on the other hand, there are many cars which are costing at a low estimate a shilling or more per mile. The two factors upon which the cost per mile depends are the initial cost and the distance covered in the year. The following figures, based upon three year’s running costs, refer to an 8 h.p. car which averaged 5000 miles per annum, and from them a very good idea may be' gathered of how small the essential expenses are. The tax amounted to £8 a year; driving license, ss; insurance, £8; repairs. but not counting tyres, as they should run for 10,000 miles and still be in serviceable condition, £3; petrol, £9 12s B^d; oil, £2 10s: grease, 5s 3d ;—total, £3l 12s Hid. To this sum it is necessary to add depreciation. On a car valued at, say, £IOO. quite 25 per cent, should be deducted at the end of the first 12 months; in later years 15 per cent, of the initial price is enough. This represents a charge the first year of £25, which, added to the above cost, makes a total of £56 12s lljd. Tins gives a running cost of less than 3d per mile. If there be no garage a further 10s a week should bo added To run the same car for 10,000 miles would cost less per mile, a-s the only increase would be for petrol, oil, and grease, and possibly repairs. For this distance the total would work out at less than 2d per mile. It isi quite a different matter to run a 20 h.p. car, because obviously the larger the car the greater are the upkeep and run ning expenses. A new 20 h.p. car cannot very well 'be run at less than 6d per mile when 10,000 are run. or lOd a mile when only half this distance is covered. One of th© chief items that have to be con side red is depreciation. It is necessary to allow a considerable percentage for this, oven in the case of a oar of first-class manufacture. On a £SOO car about 30 per cent, should be deducted the first year; in succeeding years 15 per cent, is enough. In the ease of a £SOO car depreciation -would amount the first year to about £l5O. The other costs which have to be reckoned are: —Tax, £2O- driving license. ss; insurance, £2O; repairs, £10 : petrol, calculated at 20 miles to the gallon, £SB 10s; oil, £6 8s; grease, 10s 6d. Those cost, together with depreciation, total £245 13s 6d, Or just under 6d a mile for 10,000 miles. If the oar be only used for 5000 miles during the year, the overhead charges remain the same, only the repairs, pc+rol, oil, and grease being reduced. The total cost for this distance would bo £215 or approximately lOd a mile. DUSTY ROAD DANGERS. TINY PARTICLES CAUSE ACCIDENTS. Road dust, besides being general nuisance, is ijow found to be “a fertile source of skidding.” The statement occurs in H hookht issued this week by the British Portland Cement Association, which is intended to give definite up-to-date information on the subject of concrete roads and their development in this country. (i-iii <rt‘r of dust as a cause of skidding arises from the fact that when wet the small particles form a slippery film ovei the surface, which thus becomes a grave neril to both motorists and “third parties. ’ This serious fault, inseparable from the old fashioned type of road, is absent in the case of concrete roads, whose hard surface is ajmoet incapable of disintegration into dust. ~ , . Further, the pamphlet explains, a* “aggregate” of concrete is of a gritty nature, the concrete road affords a good grip for hoof or tyro, and never wears slippery. . , Tests have been made over various Classes of roadway in the United States which already possess 32,000 miles of all-concrete road—-and figures quoted in the booklet show that an incalculable saving can be effected for ratepayers and road users by concrete construction. Annrl from the immense reduction in the cost of maintenance, a big economy is provided for t,fie vehicles using the road. The amount of pull necessary to keep a vehicle in motion after it has been started is considerably less on concrete than on any other form of toad surface, and this fact has an important bearing on tbc question of fuel economy. ENGINE WEAR. danger of dust and grit. That dust and grit drawn into the engine through the carburettor cause wear on the engine has boon demonstrated in no uncertain way: it is greater than most motorists realise. In very few rases do motor manufacturers make provision for fittine air filters on the engines, yet it would seem to be. one of Ihe most important mat tern incidental to engine durability and efficiency. The average motorist who does much driving in flm summer months is hi mil hi r Midi die swirling dust that envelopes the ear on the average road, some of which inevitably finds its wav under the lionnet, and through the carburettor into the engine, the suction into the carburettor being particularly strong. Two interesting tests recently made m Britain uro of value in conned ion with this matter. Two engines of identical make and size were run at, 2000 revolutions per minuto continuously for 24 hours, in an atmosphere saturated with dust and grit. One was fitted with an air-purifying apparatus and the other had no device of this kind. On examination at (he end of the test the engine which was supplied with purified air showed no signs of wear, while the other was definitely _ the worse for ite experience; it was unmistakable. It Ls claimed '(hat the conditions under which tho tests were conducted represented approximately, those which would be experienced in something like 10,000 miles in ordinary service. A further test was to send out sx cars—three with and three without air filters—on a tour of several thousands of miles oyer all kinds of roads. The result was a triumph for the cars using clarified air. for the carburettor of tho engines of these cars showed a minimum of wear in comparison with the others. It is quite possible that some motorist* may be disposed to the belief that these results are of more value as interesting facts than as of ultimate use in tho development of the perfect engine. But automobile engineers believe that the time will come when air-filters will bo a standard fitment to every carburettor, SPARKS. Under-inflation of tyres wastes power. Forty-throe out of 48 starters finished in the Irish 24-hours’ trial held over a 420 mile course. , "How do jou know that thief who stole your car was a professional i "No amateur could have started it.” The spirit is everything ! New Big Tree Motor Spirit is of even higher quality than pre-war.—Advt. When the armature is removed from a magneto, a piece of iron should be placed across tho polo shoes, in order to complete the "magnetic circuit," and prevent demagnetisation. A new dub has been formed in Italy, the qualifications being that the intending member must have covered 62 miles in an hour on Monza speedway, near Milan. Of tlie 45 machines which competed in the French Grand Prix 22 were of all-British construction, and several others had British component parts. The utmost mileage and speed, at lowest cost, with the new Big 'Free Motor Spirit.— It is the opinion of the Motor Cycle that it, is likely that some system of lubrication embodying the main features of the drv sump will eventually become standard practice. When one does a lot of driving along narrow lanes full of blind corners, or over road? carrying much leviathan traffic,_ the purchase of a super hoorer is a justifiable extravagance. In fact, it is more useful than an insurance policy, and not wildly expensive. . , , Motor cvcle ice-cream and soda fountains, lire “engines, taxis. G.P.O. delivery vans, and many other kinds of commercial side cars, took part in the six days’ demonstration tour arranged by the A.C.U. (England). Ford Solan does 32 mile? to gallon on "Big Tree" on non-stop run, Dunedin to Invercargill.—Advt. The Jlungarian T.T. races proved yet another Continental victory for Britisn machines, the senior and junior events both being won bv Sunbeam rider.-, while in ihe light-weight race a Viilicrs-cngined machine secured honours. . A number of Krenuti cars have standardiced a device for overcoming the dazlizng headlight problem. It L simply a .witch for putting off the headlight on too side nearest the approaching car while leaving the other full on for driving by. This is etatod to bo ealecliTo.