Rolling Resistance of flat or underinflated tires?

Topics related to Vehicle Specifications, Vehicle Acceleration Tests, Vehicle Braking Tests
MSI
Site Admin
Posts: 2302
Joined: Thu Jun 18, 2009 12:37 pm

Rolling Resistance of flat or underinflated tires?

Post by MSI »

Q: June 12, 2012: D you know of any data on the rolling resistance of flat heavy truck tires?

A: I will look into it. As a starter, the following is a reference on Drag and Steer Effects of Tires on automobile tires which i will start this thread with as i search for additional references and data particularly with respect to Truck Tires.

Drag and Steering Effects From Disablements of Run Flat Tires, Ric D. Robinette and Richard J. Fay , SAE 2000-01-1316
ABSTRACT
  • 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:
    • Drag and Steering Effects of Under Inflated and Deflated Tires,” Robinette, R.D., Deering, D., Fay, R.J. SAE 970954.
    • Drag and Steering Effects from Tire Tread Belt Separation and Loss,”,. Fay, R.J., Robinette, R.D., Smith, J., Flood, T., Bolden, G, SAE 1999-01-0447
    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. Vehicle handling and response characteristics were evaluated during and after a disablement of a zero pressure run flat tire.
OBSERVATIONS
  • The drag and lateral steering effects induced from the deflated zero pressure (run flat) radial tires were less severe than the drag and lateral steering effects from either a deflated conventional radial tire, or an inflated or deflated conventional radial tire with the tread belt detached.
  • A tire disablement with the zero pressure (run flat) radial tire exhibited minimal feedback to the driver in terms of ride quality or vehicle handling responses, or in terms of visual detection from deformation or bulging of the tire side wall profile.
  • Moderate steering at highway speeds, or aggressive steering inputs near limit conditions with a deflated zero pressure (run flat) tire did not exhibit significantly detectable different vehicle responses than the inflated tire. Some minor sluggishness and under steer may have been present with a deflated front tire position when the test tire was at the front outside position, for example when steering left with a right front test tire position. The effects were minimal when the deflated tire was at a rear tire position, or at a front inside position, for example when steering right with a right front test tire position.
  • The experimental results indicated that a tire disa blement with the zero pressure (run flat) tire was unlikely to lead to a loss of control without additional factors being present, such as severe in-use or severe driver induced factors.