The TeraFlex linear coil approach is perfectly engineered to the lifted spring of the jeep wrangler. They have extensive rate tuning and a dynamic balance between the front and the rear load that is bias to produce coil springs that offer great highway and off road performance. teraFlex used the proven linear rate technology that is preferred by many car manufacturers even those for the jeep. The results of this is active coils under load, shock valving and pairing which is consistent with the full range of suspension movement. It has predictable handling that meet requirements for a jeep that is fully required for off road travel. They have been shot peened so as to reduce fatigue and sag of the springs.