Southwest Research Institute, San Antonio, Texas, January 12, 1994
In January 1994, the U.S. Government required a drastic reduction in the amount of sulfur allowed in diesel fuel sold in the U.S. Sulfur occurs naturally in fuel and was used as a lubricant. When it was removed, diesel engine owners all over the U.S. complained about less power (an unfounded complaint based on dyno tests). A more serious problem, and a justified one, was the O-ring corrosion in diesel powered vehicles. The Southwest Research test was conducted to be sure we did not add to this problem. Old high sulfur fuel had a hardness factor of -8. New low sulfur fuel has a hardness factor of -15. This test shows that fuel blended with RxP Diesel Dynamizer has a hardness factor of -10. This does not bring the lubrication back to the old high sulfur rating, but it is an improvement over the new low sulfur fuel.