the #700 Supreme 700 and #151 Moly Bond x-200 15w40 TBN has recently been upgraded from 10TBN to 12TBN. This upgrade will result in increased protection against any acids that are formed by the combustion of the diesel fuel or by the EGR system found on the new 2003 low emission engines. Though the TBN of these oil have increased, this increase does not affect the engine oil. Both of these engine oils use an all calcium based detergent additive package that not only effectively neutralizes any acidic components that may be formed but also provides excellent TBN retention over the engine oil's drain interval.
Most heavy duty diesel engine oils contain either high magnesium based or a calcium/magnesium based detergent/dispersant additive system. Magnesium based detergent systems, though they will neutralize acids as they are formed, do not have the same effective acid neutralizing capabilities as an all calcium based additive system. Magnesium based detergent additive systems do not neutralize any of the weak acids that may have been formed by the combustion of the diesel fuel. These weak acids over time can build up in the engine oil eventually causing the engine oil to rapidly lose its TBN retention.
Magnesium based detergents are primarily used in the formulation of passenger car engine oil formulations because of their ability to allow these engine oils to pass the various engine sequence tests used to measure wear protection. However, in heavy duty diesel engine oils magnesium based detergents can cause higher wear in the ring belt area of a diesel engine. Magnesium based detergents form Magnesium Oxides when they neutralize acids, a by product of the acid neutralization reaction. Magnesium oxide is very hard in consistency and can abrade and polish cylinder walls.
Calcium based detergents on the other hand form calcium sulfates when they neutralize acids. Calcium Sulfate is very soft and fluffy in consistency and is soluble in oil. Calcium based detergents in addition have been found to enhance a diesel engine oil's ability to provide excellent high temperature piston cleanliness, provide excellent protection against bore polishing and enhance the soot handling capabilities of the engine oil.
Most heavy duty diesel engine oils contain either high magnesium based or a calcium/magnesium based detergent/dispersant additive system. Magnesium based detergent systems, though they will neutralize acids as they are formed, do not have the same effective acid neutralizing capabilities as an all calcium based additive system. Magnesium based detergent additive systems do not neutralize any of the weak acids that may have been formed by the combustion of the diesel fuel. These weak acids over time can build up in the engine oil eventually causing the engine oil to rapidly lose its TBN retention.
Magnesium based detergents are primarily used in the formulation of passenger car engine oil formulations because of their ability to allow these engine oils to pass the various engine sequence tests used to measure wear protection. However, in heavy duty diesel engine oils magnesium based detergents can cause higher wear in the ring belt area of a diesel engine. Magnesium based detergents form Magnesium Oxides when they neutralize acids, a by product of the acid neutralization reaction. Magnesium oxide is very hard in consistency and can abrade and polish cylinder walls.
Calcium based detergents on the other hand form calcium sulfates when they neutralize acids. Calcium Sulfate is very soft and fluffy in consistency and is soluble in oil. Calcium based detergents in addition have been found to enhance a diesel engine oil's ability to provide excellent high temperature piston cleanliness, provide excellent protection against bore polishing and enhance the soot handling capabilities of the engine oil.
