Using additional shocks per wheel firms-up ride quality and reduces body roll, which is beneficial on heavy rigs and vehicles that are light sprung. Multi-shocks allow you to stiffen the ride without sacrificing slow speed articulation like a heavier rated spring would. They are also great for vehicles that see a lot of higher speed use on bad roads (wash board roads, ruts, dips). Another plus is that when shocks are grouped, individual shock temperature is lowered, which reduces fade.
