Varying truck tire pressure to match different operational modes can enhance vehicle performance, particularly in the areas of traction and driver comfort. Variable central tire inflation systems allow the driver to vary tire pressure while operating the vehicle. Pressure selection should assure an optimum tire deflection and footprint for each operating condition: loaded vs unloaded, highway vs off-road. Such optimization can actually improve tire performance, although there can be tradeoffs in the area of long term casing life. Proper tire pressure selection is critical.