TBN 400 stands for total base number 400, a term used to measure the alkalinity of engine oils. TBN represents the oil’s ability to neutralize acidic compounds formed during combustion and prevent them from causing damage to engine components.
TBN is an important property of engine oils, especially for high-performance and heavy-duty engines. As engine oil is continually exposed to high temperatures, combustion byproducts, and pollutants, it can become acidic over time. The TBN value represents the oil’s reserve alkalinity, specifically its ability to neutralize these acids and maintain the desired pH balance.
A TBN of 400 is considered high and indicates that the engine oil has a strong ability to neutralize acids. It is commonly found in heavy-duty diesel engine oils, where combustion products and contaminants can cause high acid levels. A TBN value of 400 ensures that the oil can effectively neutralize these acids, preventing engine damage such as cylinder liner and bearing corrosion.
When selecting an engine oil with a specific TBN, it is important to consider the manufacturer’s recommendations and the engine’s requirements. Different engine types and operating conditions may have different TBN requirements. Additionally, following recommended oil change intervals is critical to maintaining the oil’s TBN and ensuring optimal engine protection.