Inflation pressure retention is an important property of tire performance because underinflation can adversely affect tire rolling resistance, handling, structural integrity, and tread life.

This test method is useful for research and development evaluation of the effects of tire component formulations and geometry on inflation pressure retention. Testing for rate of pressure loss under static conditions is practical because of the following:

5.2.1 Tires in normal use are predominantly at rest, and

5.2.2 Relative air diffusion rates of various tires in normal intermittent road service will correlate with static relative rates, to a first approximation. The relative air diffusion rates of different tires may not be quite the same under dynamic flexing as when tested statically, but the difference is believed to be small.

The results from this test method are not suitable for inferring tire inflation retention under severe service conditions, such as heavy cornering or impacts, that might cause significant air loss at the tire-rim seal.

1.1 This test method covers the determination of the rate of inflation pressure loss resulting from air diffusion through the structures of tubeless tires under constant temperature conditions. The testing is done under static conditions, that is, nonrotating, nonloaded tires.

1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.