Formulas are developed for the optimum spring and damper rates in conventional car suspensions. The formulas are based on the minimization of the mean-squared tire forces on random roads and take into account the body k2 /ab ratio. The suspension spring rates are optimally tuned in relation to the tire radial rates and the optimal spring and damper rates are independent of speed. Frequency locus methods are employed in the theory which is based on a linear half-car model. An example demonstrates the important effect of body centre of gravity position on suspension performance and overall static stiffness.