The high frequency dynamic testing shows that the longitudinal coefficient nearly doubles with the use of 50 phr BIMS, in comparison to the sSBR/NR control.
The high-frequency acoustic temperature sweeps also show that the maximum of the longitudinal coefficient values is shifted to higher temperatures with increased use of BIMS (table 6; refs.
Where [k.sub.x] is tire longitudinal stiffness, [[mu].sub.x] is longitudinal coefficient
of friction, and [q.sub.z] represents the normal force distribution.
It should be clear that estimating the lateral and longitudinal coefficients
of friction are critical in establishing the Performance Envelope and that this definition of Effective Friction accounts for losses due to factors including excess understeer, brake proportioning, load transfer, and powertrain limitations.