Search Results

Due to engine oil consumption, over 90% of the incombustibles in the diesel particulate filters (DPF) are derived from organometallic lubricant additives. These components are derived from calcium and magnesium detergents, zinc dithiophosphates (ZnDTP) and metal-containing oxidation inhibitors. They do not regenerate as they are non-volatile metals and salts. Consequently, the DPF has to be removed from the vehicle for cleaning. Ashless oil could eliminate the need for cleaning. This study initially focused on development of an ashless oil, but eventually concluded that this oil could not meet the valve-train wear requirements of the API CJ-4, SN/ACEA E9 oil categories. However, a zero-phosphorus oil with no ZnDTP and an extremely low sulfated ash of 0.4% demonstrated that it could meet critical engine tests in API CJ-4/ACEA/SN. The above oil, which has been optimized at 0.3% sulfated ash, has proven field performance in Cummins ISX with DPF using ultra low sulfur diesel (ULSD).

The ability of oil to retain its viscometric properties is particularly important in Heavy Duty Engine Oil applications to prevent wear and maintain intended levels of oil pressure. It is known that mechanical shearing of the oil, fuel dilution, oil oxidation and soot level all affect the aged oil kinematic viscosity at 100°C (KV100). For API CJ-4, as well as for many OEMs, an oil's KV100 must stay within the original viscosity grade as defined by SAE J300 after 90 cycles in the Kurt-Orbahn (KO) apparatus. This study investigates the effect of polymer chemistry and structure on extended shear stability of lubricating oils by evaluating the performance of two Viscosity Index Improver (VII) chemistries, Olefin Copolymer (OCP) and Hydrogenated Styrene Isoprene (HSI), under more severe shearing conditions than required for CJ-4. These technologies were evaluated in the KO shear test up to 700 cycles and the KRL shear test up to 8 hours.

By 2014, all new on- and off-highway diesel engines in North America, Europe and Japan will employ diesel particulate filters (DPF) in the exhaust in order to meet particulate emission standards. If the pressure across the DPF increases due to incombustibles remaining after filter regeneration, the exhaust backpressure will increase, and this in turn reduces fuel economy and engine power, and increases emissions. Due to engine oil consumption, over 90% of the incombustibles in the DPF are derived from inorganic lubricant additives. These components are derived from calcium and magnesium detergents, zinc dithiophosphates (ZnDTP) and metal-containing oxidation inhibitors. They do not regenerate as they are non-volatile metals and salts. Consequently, the DPF has to be removed from the vehicle for cleaning. Ashless oil could eliminate the need for cleaning.

A range of tools including analytical, bench, and engine tests have been used to investigate the viscosity increase mechanism and formulation appetite of the Sequence IIIG engine test. As commonly observed with high temperature tests, the Sequence IIIG has a strong appetite for antioxidants. Base oil also has a strong impact. Base oil volatility has a direct physical impact on viscosity due to the evaporation of light base oil components and the resultant increase of non-volatile additive components. Volatility characteristics are dependent on the distribution of volatile fractions. The relative oxidation and volatility contributions to viscosity increase have been compared between the Sequence IIIG and Sequence IIIF. The impact of base oil volatility is greater in the Sequence IIIG than the Sequence IIIF test.

The ASTM Sequence VIB is the new fuel economy standard for ILSAC GF-3. The new test pushes the bounds of current engine oil technology. With concerns over Corporate Average Fuel Economy (CAFE) targets, the auto manufacturers have been strong advocates of the Sequence VIB. This paper describes findings of some of fuel economy studies for GF-3. The Sequence VIB is a significant step relative to the past Sequence VIA test in requirements for friction control. Stage-by-stage analysis indicates a shift to a higher degree of “mixed” lubrication response in the Sequence VIB relative to the Sequence VIA, 35 % versus 11 %, making both optimized friction modification and viscosity control necessary for obtaining high levels of fuel economy for GF-3. Viscometric contributions are controlled by both the (high temperature - high temperature) HTHS and basestock viscosity of the oil. Minimizing these viscometric measurements leads to improved fuel economy.