Synthetic Diesel Oil That Performs With New Standards Set in 2007

New emission standards go into effect in 2007 that require more stringent nitrous oxide (NOx) and particulate emissions reductions in on-road light- and heavy-duty diesel vehicles, and most engine manufacturers have incorporated increased exhaust gas recirculation (EGR) rates of 25-35% to meet them.

New low-emission engine models with high EGR rates dump excessive amounts of soot and acids into the oil, accelerating wear in the cylinder walls. Increased EGR rates also mean 2007 diesel engines run hotter than their predecessors, requiring diesel oils with improved oxidation resistance to prevent thermal runaway and maintain engine protection.

The introduction of Ultra Low Sulfur Diesel (ULSD) fuel in June 2006 dropped diesel fuel sulfur levels from 500 ppm to 15 ppm in order to meet 2007 particulate limits, provide compatibility with NOx after-treatment systems and enable high EGR rates. In addition, in order to further reduce particulate emissions, diesel particulate filters (DPF’s) have been incorporated into all 2007 American diesel engines, forcing diesel oils to balance engine protection with DPF life.

Increased EGR, although effectively decreasing NOx emissions, results in less efficient combustion and increased levels of soot. Traditionally, detergent additives in diesel oils have effectively prevented power-cylinder wear, piston deposit formation, oil consumption, rust and valve train wear, while an additive known as ZDDP has effectively provided wear protection for the valve train system and other components, as well as oxidation inhibition. The problem, however, is that ZDDP and many detergents contain ingredients that plug diesel particulate filters, including sulfated ash, phosphorus and sulfur.

Due to the negative effects of sulfated ash, phosphorus and sulfur on diesel particulate filters, ASTM agreed to accept limitations in these areas and incorporate new additive chemistry for diesel oil category CJ-4.

Sulfated ash provides lubricity and alkalinity (TBN) to counteract acid formation during combustion. While most API CI-4 oils are composed of 1.50 percent ash, new API CJ- 4 diesel oils are limited to 1.0 percent ash, dropping TBN levels from 10 to 14 with average CI-4 oils to eight with CJ-4 oils. Lower sulfated ash, phosphorus and sulfur levels, as well as increased soot loading, affect an oil’s ability to provide protection over extended drain intervals.

AMSOIL Synthetic 5W-40 Premium Diesel Oil (DEO) is the premium choice AMSOIL diesel oil for model year 2007 and newer heavy-duty and pickup truck diesel engines requiring API CJ- 4 emission quality oil standards. It delivers extraordinary lubrication in diesel engines found in commercial, fleet and personal vehicles.

Formulated with the latest additive technology and the most advanced synthetic base oils, AMSOIL Synthetic 5W-40 Premium Diesel Oil exceeds the higher performance demands of modern engines. It withstands the stress of heat, soot and acids to help prevent deposits, corrosion and wear, and its broad viscosity range offers superior protection over a wide temperature range. Synthetic 5W-40 Premium Diesel Oil resists breakdown and is recommended for the longest service interval established by the engine, vehicle or equipment manufacturer. Drain intervals may be extended based on oil analysis.

AMSOIL Synthetic 5W-40 Diesel Oil is a low sulfated ash, phosphorus and sulfur formulation that meets and exceeds modern specifications for emission quality diesel oil. It is compatible with all exhaust treatment devices and is designed to extend the service life of particulate filters.

AMSOIL Synthetic 5W-40 Premium Synthetic Diesel Oil replaces 5W-40, 10W-40 and 15W- 40 viscosity oils, and is “backwards compatible” with pre-2007 diesel engines. Synthetic 5W-40 Premium Diesel Oil may be used in pre-2007 diesel engines, but for increased protection and performance for extended drain intervals, AMSOIL still recommends Synthetic Heavy Duty Diesel & Marine Motor Oil (AME), Series 3000 Synthetic 5W-30 Diesel Oil (HDD), Synthetic 10W-30/SAE 30 Diesel Oil (ACD) or Synthetic Blend 15W-40 Gasoline and Diesel Oil (PCO).

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