The introduction of Ultra-Low Sulfur Diesel (ULSD) started in 2006 has brought new problems to the world of diesel-equipped trucks.  The new change in sulfur requirements has greatly affected the naturally occuring lubricating properties of #2 diesel.  During the desulfurization process, the severe hydrotreating needed to lower sulfur levels in diesel fuel to the required <15ppm levels has resulted in a loss of petroleum aromatics that are critical to the lubricating ability of the fuel.  The removal of sulfur and aromatics from the fuel directly affects the fuel's ability to properly lubricate many fuel system components that rely on the fuel for lubrication and cooling. Fuel system components such as fuel transfer pumps, fuel injection pumps, and fuel injectors, all rely on the fuel's lubricity to maintain proper lubrication. With the transition into full ULSD use, these components have become vulnerable to increased wear, inadequate lubrication, and increased temperatures which could ultimately result in component failures.