HIGHER SPEED MOTOR VEHICLES

Timaru Herald, Volume CXXV, Issue 18629, 26 July 1930, Page 10

HIGHER SPEED MOTOR VEHICLES

GIVE LESS TYRE MILEAGE. The last few years have seen marvellous developments in motor car construction. More good roads have created a demand for higher speed cars and this demand has been foreseen by motor car manufacturers with the result that faster and faster cars are being produced, says a tyre expert in the Goodyear News.

Tyre manufacturers have established, through a series of interesting tests, that tyres wear out much faster at high speeds that at low speeds, not only because more heat is developed in the tyre, but because the abrasion is much greater. For example, a grindstone operated at high speed will 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 to 35 miles, now are speeding up to 40, 45 and 50 miles per 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 miles per hour. Some time ago certain cars were run at approximately 45 miles an hour, keeping up this speed as uniformly as i possible and taking curves with prac- . tically no slowing down. Later the i speed was reduced to 35 miles per hour i maximum and immediate increase in i tyre mileage was noted. In fact tyres which ran about 6,000 miles at high speed, gave nearly 12,000 miles when ’■ driven at normal speed, i When a car is driven at high speed, • there is a great deal more tyre slip- ■ page due to swerving from one side i of the road to the other and to the ■ continual axle bounce resulting from - inequalities in the road, which are t magnified by the speed.—“ Goodyear f News.”