The Effect of Tire Non-uniformity on Engine Power Loss

An ideal tire should be completely uniform in geometric dimension, mass distribution and stiffness coefficient. Under such conditions, the tire would rotate without any unwanted and harmful vibrations and/or force alterations delivered to the vehicle body as it moves. However, the ideal conditions are only theoretically possible and cannot be the case in actual conditions. Accordingly, a tire has some non-uniformities in actual conditions. This paper aims to study the lost energy of a non-uniform tire of a passenger car. To achieve this, the vertical force on the tire, which is due to initial loading and also each case of non-uniformity, was analytically calculated. Then, the equations were simulated in MATLAB software package. This was followed by comparing the frictional force between the tire and ground to the engine force to calculate the power loss. Finally, the value of power loss as a result of all kinds of tire non-uniformity was evaluated.