How To: Calculate Savings from Conversion to Advanced
Lubricant
Tom Dietz, Retired—Global Industrial Lubricants Technical Manager, ExxonMobil Fuels &
Lubricants
When companies switch from conventional lubricant to a high-performance synthetic,
they expect to see a number of potential benefits related to enhanced safety and
improved environmental care. These potential benefits, which can include extended oil
drain intervals, enhanced energy efficiency and more reliable equipment performance,
may not all be experienced immediately.
That’s why it’s important to know how to properly measure and evaluate lubricant
performance, as well as how to document productivity gains, so you can always have
an accurate picture of your return on investment when it comes to switching to highperformance synthetic lubricants.
When trying to understand the benefits associated with a lubricant change, you must
assess cost over time.
For accurate results, it is critical to ensure that you have captured all of the appropriate
costs and benefits over an equivalent period of time.
Savings over Time = (Costs associated with Lubricant A) – (Costs associated with
Lubricant B)
Follow the guidelines below to ensure that you are properly calculating the benefits of a
lubricant conversion:
Compare Apples to Apples
When comparing cost of operation with one lubricant to cost of operation with another,
always ensure that you are evaluating expenses over an equivalent time period. This
consideration is critical to the ultimate assessment, as synthetic lubricants often provide
lengthened drain intervals. So, if one lubricant offers oil drain intervals that are 50
percent longer than the other lubricant being assessed, you must calculate the costs
and benefits of each lubricant technology over a the same time in operation to
accurately evaluate the performance.
In the example of a conversion to a lubricant offering 50 percent longer drain intervals,
your comparative assessment would reveal three fill and drain intervals with the original
lubricant for every two fill and drain intervals of the synthetic.
Assess the Investment
When evaluating a lubricant conversion, it is important to recognize that there may be
one-time costs associated with converting operations from one lubricant to another, and
these costs should be factored into the calculation.
For example, to experience the full benefit of the replacement lubricant, you may need
to perform a complete system flushing or cleaning, which would have an incremental
cost associated. This cost will need to be subtracted from the overall savings accrued
through conversion.
Be sure to consider the following aspects when totaling associated costs:
! Price of Lubricant and Consumables
Total the cost of lubricant in operation using the delivered pricing of each product to
your plant site. Make sure that you are evaluating the cost of the two lubricants based
on the same packaging style, when appropriate. Additionally, capture the cost
associated with consumable parts, such as filters.
! Price of Disposal
Capture the cost of disposal for the used lubricant over equal time for each trial and
include in the total cost of operation.
! Price of Labor
Often, switching to a synthetic lubricant will reduce the amount of labor associated with
routine maintenance, as fewer oil drains translate to less time spent changing oil. A
reduced cost of labor will translate to a credit toward the overall cost of conversion to a
synthetic.
Evaluate Overall Energy Consumption
The difference in energy consumption required to power an application will vary
between lubricant technologies. Differences in energy efficiencies of lubricants can be
small—often smaller than 3 percent—making it challenging to determine the overall
cost of energy in a particular application. It will be necessary to ensure that you are
capturing these values in controlled environments and take care to maintain ambient
temperature and humidity conditions throughout the test.
In laboratory testing, we generally run efficiency tests multiple times and compare the
outcome values. Then, we compare the results of the tests to determine if there is a
variance in the efficiency values between trials. If the results of the second test of the
same lubricant are significantly different than those of the first, additional data may be
required in order to understand overall energy consumption of the two lubricants.
If energy consumption is reduced, then emissions have likely diminished,
proportionally, potentially resulting in associated credits. At ExxonMobil, we currently
assess the value of emissions reductions using an estimate of USD $30 for each
reduced ton of CO2.
Hopefully, by using the above methods, you will be able to demonstrate similar
advantages of a lubricant conversion at your site, and don’t hesitate to consult with your
Mobil Field Engineering Services representative for help with the evaluation of situations
at your location.
How To: Calculate Savings from Conversion to Advanced Lubricant by Tom Dietz reprinted with permission of the Mobil
SHC Club. All Rights Reserved.