GotQuestions? Lubricants

Q. What's the difference between TBN and TAN in an oil analysis?

March 17, 2014

SHARING TOOLS        | Print Subscribe

A. TBN is total base number and TAN is total acid number. TBN is a measure of the reserve alkalinity or reserve acid neutralization remaining in the oil. TAN measure the increase of oil oxidation and build-up of corrosive acidic compounds. Engine manufacturers often recommend utilizing both tests to gain a more in depth understanding of oil condition and engine oil remaining protection. In utilizing both tests, the TBN will decrease over time and TAN will increase over time. The point where the two numbers meet or cross over can be considered the point where the oil can no longer provided adequate corrosive where protection.

Comment On This Story

Email: (Email will not be displayed.)  
Comment: (Maximum 2000 characters)  
Leave this field empty:
* Please note that every comment is moderated.

Author Bio

sponsored by

Mark Betner

Heavy Duty Lubricants Manager

CITGO Lubricants

Mark Betner boasts 35 years of experience in the lubricants business. As the Heavy Duty Product Manager for CITGO Lubricants he is responsible for initiating and implementing the marketing of new products and human development programs and oversees communications with the media, trade shows and consumer education.

Prior to this, he was a field sales manager and technical training administrator at an independent lubricant company specializing in heavy equipment lubrication.

Mark earned a master’s and bachelor’s degree in both chemistry and biology from Indiana University. He holds a certification from the Society of Tribologists and Lubrication Engineers and is a member of the Truck Maintenance Council.


We offer e-newsletters that deliver targeted news and information for the entire fleet industry.



The expert, Mark Betner from CITGO, will answer your questions

View All



The expert, Rence Oliphant from Hendrickson, will answer your questions

View All