Significance and Use
5.1 This test method describes a technique for assessing the performance characteristics of tires in a winter environment on snow and ice surfaces. When snow is referred to hereafter, ice is implied as appropriate.
5.2 The measured values quantify the dynamic longitudinal traction properties of tires under driving torque. Dynamic traction properties are obtained on snow surfaces prepared in accordance with the stated test procedures and attempts to quantify the tires' performance when integrated into a vehicle-environmental system. Changing any one of these environmental factors will change the measurements obtained on a subsequent test run.
5.3 This test method addresses longitudinal driving traction properties only on snow and ice surfaces. Refer to Test Methods for test methods for braking and lateral traction properties on snow or ice, or both.
1.1 This test method covers a procedure for measuring the driving traction of passenger car and light truck tires while traveling in a straight line on snow- or ice-covered surfaces.
1.2 This test method utilizes a dedicated, instrumented, four-wheel rear-wheel drive test vehicle with a specially instrumented drive axle to measure fore-aft and vertical forces acting on a single driven test tire.
1.3 This test method is suitable for research and development purposes where tires are compared during a single series of tests. They may not be suitable for regulatory statutes or specification acceptance because the values obtained may not necessarily agree or correlate either in rank order or absolute traction performance level with those obtained under other environmental conditions on other surfaces or the same surface after additional use.
1.4 The values stated in SI units are to be regarded as the standard. Ordinarily, N and kN should be used as units of force. This standard may utilize kgf as a unit of force in order to accommodate the use of load and pressure tables, as found in other standards both domestic and global that are commonly used with this standard. The values given in parentheses are for information only.
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.