The two primary functions of sway bars are to control body roll and to determine the understeer or oversteer behavior of a vehicle. Stock sway bars have low torsional spring rates because they are manufactured from small diameter bar stock or tubing. BMR Suspension?s SB045 rear sway bar was designed by factoring in the vehicle weight, application, motion ratio, coil spring rate, and adjustability requirements. Manufactured from heavy-duty 25mm bar stock, the SB045 is cold formed to better resist torsional fatigue and retain its “memory” far longer than the hot-formed bars used by many competitors. The sway bar is CNC-formed for exact manufacturing tolerances and repeatable high quality. The SB045 attaches to your S550 Mustang with 88-durometer polyurethane bushings, reducing the deflection from the stock rubber bushings. These bushings are molded from 88-durometer, low-deflection, polyurethane, and are internally fluted to keep grease in the bushing.