Drag and Steering Effects From Disablements of Run Flat Tires 2000-01-1316

This paper is the third part of a series of vehicle tests designed and conducted in order to further the understanding of vehicle handling and responses associated with a tire disablement event. The first two parts were published in SAE 970954 Drag and Steering Effects of Under Inflated and Deflated Tires [1], and SAE 1999-01-0447 Drag and Steering Effects from Tire Tread Belt Separation and Loss [2]. All of the test results included herein are presented in a manner to facilitate direct comparison to the previous test programs.

Under inflated or deflated tires are known to cause increased forward drag and lateral steering effects on vehicles. These effects are commonly suggested to be the cause of driver loss of control and subsequent vehicular accidents. The increased drag and induced steering effects of under inflated and deflated tires are frequently an issue in an accident reconstruction. In the referenced previous publications, the authors presented vehicle handling response for a range of passenger vehicles that included replicated testing of vehicle handling during and after an air-out disablement, and the results of replicated testing of highway speed tread belt separation test results for a mid-size front wheel drive four door sedan. The authors have collectively been involved in the testing of multiple sudden air-out disablements and forced tread belt detachments involving passenger cars.

This publication addresses a similar series of tests which were conducted to obtain comparative drag and lateral steering effects after the disablement of current generation zero pressure, or run flat, type of tires such as those equipped on some upper end vehicles in recent years. These tests were conducted in accordance with the test protocol defined in SAE 970954 [1]. Vehicle handling and response characteristics were evaluated during and after a disablement of a zero pressure run flat tire.