The rear springs lower the car almost 2 inches for this. Much more than the advertised 1.18. With all 4 springs installed and after a week of driving it was clearly noticeable that the rear part sags more than the front part. S550 Mustang owners, do not buy. @Whiteline, more homework needs to be done. The photos show how the car was after installation in the spring and a week's driving. Ground clearance at the rear is lower than at the front.