STLE tackles the tribology of electric vehicles

Dr. Robert M. Gresham, Contributing Editor | TLT Lubrication Fundamentals September 2018

New research project will study the trends and technical issues most impactful to lubricant manufacturers.

© Can Stock Photo / vlaru
In recent articles, I have taken trends or implications from the 2017 STLE Emerging Trends Report, (available free on and tried to expand on a particular topic. At the 2018 STLE Annual Meeting in Minneapolis, Minn., an ad hoc group, guided by STLE Past President Martin Webster of ExxonMobil Research & Engineering, met to discuss another trend hidden in the report. This has to do with the global growth of electric vehicles (EVs). 

As the group defines it, EVs are a mode of transportation that in some way uses electricity to provide locomotion. This ranges from so-called pure electric vehicles, which operate with energy provided exclusively from batteries, to various forms of hybrids, which combine other modes of locomotion energy such as a gasoline engine with electric power locomotion. As you might expect, one of the key topics was: What are the implications of EVs on the tribology community?

For more perspective, one of the interesting notables from the trends report was the finding that the thinking on EVs varied by geography/demographics. In all cases, the goal is less reliance on fossil fuels, reduced emissions, higher energy efficiency (recall that in a conventional gasoline engine only 21% of the energy consumed is actually used to move the car forward) and, of course, practical operating costs for vehicle owners. 

However, emphasis on the relative importance of these goals is not uniform. For example, in Europe there is more interest in pure EVs, likely due to overall population density combined with perhaps less-daunting electric grid distribution problems and more reliance on nuclear power. In Asia, Japan in particular, the emphasis is on more hybrid technology. Perhaps this is because they are looking for the most global, generally applicable solution, regardless of geography.

In the U.S. there is certainly interest in both but also significant interest in how to make existing gasoline and diesel engines more energy efficient than the current 21%. This would be because we have areas with both very high population density (East and West Coasts) and areas with little population such as Wyoming, the ninth largest geographically but 50th in population. Pure electric vehicles would simply not be a solution for much of Wyoming.

What are the implications of this enhanced global interest in EVs? First, especially in other countries and within the OEMs, there is increased research funding. Some of the areas of interest, many of which have tribology implications, are different drive train options, new materials for weight reduction plus different duty cycles, loads and speeds. Some of the big problems with battery technology are charging cycles, weight reduction, thermal management (heat resistance and cooling), toxicity of materials and always cost. Fluids now may have to be formulated around thermal resistance, cooling efficiency and dialectical properties (more or less conductivity) as well as the usual desire for reduced friction, wear, toxicity, etc.

Based on the meetings held at STLE’s last annual meeting, there appears to be considerable interest within STLE and, for certain, within other organizations such as the Faraday Society in the UK. What are we to do?

In the future there will be additional articles in TLT outlining the exploration of these topic areas. We expect to create an STLE technical committee, host sessions—which could be papers, forums or panel discussions—and have keynote or plenary speakers at our conferences and perhaps at other venues as well. If this is an area of interest to you or if you would like to volunteer to be involved in this project, please contact me at the address below or Martin Webster at
Bob Gresham is STLE’s director of professional development. You can reach him at