What is TBN? And how much do I need?

What is TBN? TBN is known as the Total Base Number, this is a measured level of Base Reserve built into the additive package, known as reserve alkalinity. Reserve alkalinity is measured in milligrams of potassium hydroxide per gram (Reported as mg KOH/g) it is designed to neutralize harmful acids that are produced during the engine combustion process. The higher the TBN value, the more reserve alkalinity or acid neutralizing ability the oil contains. The alkalinity compounds are used to fight against organic, sulphurous and sulphuric acids formed in the oil.

So should we all use a High TBN oil? There are advantages, but there are also disadvantages of using a High based TBN oil (known as High Overbased Sulphonates) it's not just because the price is much higher. High TBN oils can produce high ash content that can impair engine efficiency and cause loss of power, this will lead to excessive deposit build-up on pistons and valves. High ash is caused by non-combustible residue of an oils detergent additives, these additives contain derivatives such as barium, calcium and magnesium. These deposits can lead to the following devastating results:

  • Ash deposit build-up on pistons and valves
  • Loss of oil stability
  • Polishing of cylinder line bores
  • Valve Guttering
  • Loss of power
  • Increased oil consumption
  • Increased fuel consumption

To understand TBN and figure out how much TBN is needed in oil, we first need to have some knowledge of the sulfur content contained in diesel fuel. Sulfur content varies from one country to another.

An example: In Australia the government legislation requires Diesel fuel at the bowser to have a maximum sulfur content (ULSD-Ultra Low Sulfur Diesel) of 10ppm (10mg/kg). The chart below illustrates the two most common diesel fuel standards used throughout the globe as the basis of reducing Sulphur and harmful emissions. You need to know the sulfur content to determine what TBN concentration level is needed in engine oil.

The illustration below demonstrates that TBN values for Direct Injection (DI) Engines were generally calculated to be 10x the Sulphur content and for a Precombustion Chamber (PC) Engine, it was calculated at 20x the Sulphur content.
However, when the Sulfur exceeds 1.5%, then consider using an EOM Recommend specifications to maintain adequate wear protection.

It was considered to be abnormal when the TBN deteriorates to 50% of the New oil TBN value. Meaning the oil needed to be changed because it has lost the ability to neutralize acids. With increased emission controls, Sulfur diesel fuels are now very low (ULSD), TBN values reflect these changes by having a New TBN value of generally around 8 or 9 mg KOH/g.

High TBN oils do not necessarily mean that the oil is better than that of a lower TBN oil. A High TBN oil has greater capabilities of counteracting acids.
Unnecessary High TBN oils can produce ash build-up that will cause sequential effects to your engine.
Consider using an OEM recommended oil specification to ensure adequate wear protection.

Find out the Sulfur content in your diesel fuel, have your oil analysed, and check OEM recommendations, from this information, you can make clear decision on which oil is best suited for your engines performance and well-being.
Contact Techenomics if you are still unclear on how much TBN your oil should contain.

To enquire about TBN please contact Jason Davis, email: jason.davis@techenomics.com or visit https://www.techenomics.net .
For media enquiries please contact Brooke Tolar, DragonFly Public Relations on T: 0411 553 246 or E-mail: brooke@dragonflypr.com.au

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Techenomics has distributed specialty lubricants to the mining industry throughout Australia and Indonesia for more than 20 years with the business steadily growing into other parts of the world. In 1988, Techenomics introduced proactive condition monitoring and fluid management services.
Today, Techenomics focuses on its Total Fluid Management Services (TFMS), operating ISO 9001 accredited laboratories and consulting services. These laboratories all conduct lubricant analysis on used oils and greases, and analysis of wear debris. TFMS is operated by site-based teams who establish and maintain condition monitoring programs, and manage the total lubricant cycle at the clients’ facilities.
Techenomics’ consulting services focus on tribology; lubrication practices, product application, component wear, lubrication management and training programs. Its engineers design and builds unique solutions to improve component life. Its training programs are not generic programs, they are custom developed for clients and aim to eliminate customers’ specific problems and are always results-orientated. These consulting services are often used in continuous improvement programs.
Techenomics’ lubrication and fuel services reduce maintenance costs for mobile and fixed plant equipment, irrespective of the industry.