PROPER INFLATION.

Hawera Star, Volume XLVII, 28 July 1928, Page 15

PROPER INFLATION.

DISREGARDED BY SOME CORRECT PRESSURE BEST. Proper inflation, although highly disregarded hy some motorists, is gratiaailiy sinking into the consciousness of many since it is the nrst prmcip.b that the average car-owner Jearns in regard to tyres. A few yeans ago, when high pressu.e tyres were in cogue, it was not as necessary to keep inflation up to a certain point since a casing innated to tiO pounds pressure could drop Ulb and the loss would be hut 10 per cent. Tyres were less flexible and, in general, built of many pi.es of tabric. .Put the balloon tyre must be very flexible to give the' usual riding comfort demanded by the car-owning public, and carries much less pressure. A Joss of 61i> pressure in a balloon tyre designed to carry but 301 b means a loss of *0 per cent, in inflation. In the first instance the enect was negligible. in the second instance it is much more serious. By actual test, two sets of tyres, one run at recommended inflation and the other Gib under-inflated, showed a difference of mileage of 25 per cent. Under-inflation permits the casing to flatten out, causing more road friction and wearing the tread rubber over a wider area. But, more serious than this, too low pressure may break the body or carcase of the tyre by tire resultant excessive strain 011 the cotton strands or cords. This is especially true if the tyre should hit a piece of sharp rock or any other road obstacle. And high average speeds accentuate this condition. If such an object is run over by the undorintinted casing, there is not enough air to absorb the terrific strain in the t\ re.