PRICE OF SPEED

Rotorua Morning Post, Volume 2, Issue 356, 18 October 1932, Page 2

PRICE OF SPEED

FAST DRIVING NOT CONDUCIVE TO ECONOMICAL RUNNING. PERFORMANCE AFFECTED. j Motorists who complain that they cannot get satisfaetory petrol mileage from their cars, tbat oil eonsumption is too high, and that the tyres do not last as they should ara prone to blama the garagenian or the tyr'e manufacturer. It may be that Smith and Jones own models of the same make and date, and whereas Smith can boast that he ordinarily does 28 milas to the gallon, hardly ' 'ever has to refill the crankcase with oil, and covers perh'aps 12,000 to 15,000 miles on a set of tyres, Jones is wroth because the performance of his car in those respects in only 60 per cent. of that of his neighbour. Righly ha feels that something is amiss, and being very human he lays the blame everywhere but at his own door. But if he is a fast and "heavy" driver he will not have to look far afield for the true explanation. For the man who is anxious to keep his motoring bills as low as possible fast driving is an expensive luxury, and he must understand that the claims of car and tyre manufacturers as to petrol mileage and tyre life which may be expected are very sensibly based on the assurnption that the vehicle will be capably driven at moderate average speeds. It has been stated by one of the best-known tyre companies that the wearing down of the tread of the tyre is twice as rapid at 45 m.p.h. as it is at 35m.p.h. Now, in order to average, say, 28 m.p.h., on a long run, much of the distance must covered at 35 m.p.h.; but if the motorist lilces more speedy travelling and tries to keep up an average of, say 33 m.p.h., then for a great part of the time the speedometer will hover round 45 m.p.h. Here, then, is one explanation of the complaints that are sometimes voiced as to the alleged poor qualities of tyres. But if the ear-owner is not only a fast driver, but one who also has a rough touch on the accelerator and "drives on the brakes," the wear and tear will be increased most seriously, particularly if the vehicle is stopped and started frequently during the journey. Expert trials have shown that where a car was driven at 35 m.p.h. and stopped and started every quarter of a mile during a long test drive the wearing down of the treads was astoundingly greater than when on a similar run the car was stopped and started only every mile. In like manner, speed and bad operatiqns of the , accelerator have a very marked influence on fuel eonsumption, and it is quite illogical to expect that a car for which a normal petrol mileage of 35 m.p.g. is elaim— ed will travel that distance to the i gallon if it is driven at a average speed of 45- or 50 m.p.h. Add to these convincing facts, the strains and stresses which speeding imposes on all the working parts and one will j realise that although pace may be I pleasant there is a price to pay.