Paper Number 6.1
Inflation Pressures at Less-Than-Maximum
Tire Loads
John W. Daws, Ph.D., P.E.
Daws Engineering, LLC
4535
Email: jdaws@dawsengineering.com
One of the most important parameters to be
established for tire operation, whether on a new vehicle being designed by a
vehicle manufacturer or on a plus-size fitment, is the recommended cold
inflation pressure for the tire. The
tire carries a maximum inflation pressure label, but operation at lower loads
and pressures is generally beneficial for overall vehicle performance. Recommended inflation pressures have
historically been provided by tire standards organizations in the form of
tables of load versus pressure or in the form of simple mathematical
models. This paper reviews these models,
and develops a new formulation based on a tire stiffness model. It is shown that the stiffness model predicts
higher inflation pressure requirements at lower-than-maximum loading conditions
than some of the models in use in the industry.