HIGHER SPEED VEHICLES

Sun (Auckland), Volume II, Issue 320, 3 April 1928, Page 8

HIGHER SPEED VEHICLES

[ GETTING LESS TYRE MILEAGE i 3 The last few years have seen marvel--1 lous developments in motor-car con--1 struction. More good roads have cre- ' ated a demand for higher speed cars and this demand has been foreseen by motor-car manufacturers with the re- ’ suit that faster and faster cars are be- • ing produced, says a tyre expert in the “Goodyear News.” 5 Tyre manufacturers have established, through a series of interesting tests, j that tyres wear out much faster at | high speeds than at low speeds, not only because more heat is developed in i the tyre, but because v the abrasion is much greater. For example, a grindstone operated at high speed will i sharpen a knife much quicker than when run slowly. [ Motorists who, two or three years ago ■ maintained an average speed on the highways of 30 or 35 miles, now are i speeding up to 40, 45 and 50 miles an hour. But the motorist who drives his • car at normal speeds is certain to get ! more mileage than the individual who covers long distances at from 45 to 60 j miles an hour. Some time ago test cars were run at : approximately 45 miles an hour, keep- , ! ing up this speed as uniformly as pos- j | sible and taking curves with practic- I ally no slowing down. Later the speed I > ; was reduced to 35 miles an hour maxi- j ■ j mum and an immediate increase in tyre 1 L ! mileage was noted. In fact, tyres which I j | ran about 6,000 miles at high speed, j . ! gave nearly 12.000 miles when driven : | at normal speed. j When a car is driven at high speed, there is a great deal more tyre slippage - ; due to swerving from one side of the - ; road to the other and to the continual r ! axle bounce resulting from inequalities 1 ■> r i in the road, which are magnified bv the 1 - j speed. . i Seven out of every ;j 0 r»ars ir. i j Paris are driven by woifien, but < nr. - | three women are involved in every 100 j fines imposed.