Additive depletion in engine oil and the effects on tribology performance

Lead Research Organisation: University of Leeds
Department Name: Mechanical Engineering


Engine manufacturers are facing a growth in demand on how they can increase and lengthen oil change intervals of lubricants, therefore reducing the total cost for customers over the life of an engine, as well as reducing the impact of waste oil on the environment. However, to improve engine oil properties, several additive elements are added to engine oil, which reduce friction and wear and enhance oil properties during harsh working conditions. Over the lifespan of lubricating oil, additive elements are influenced by oil contaminations such as soot and water. Soot particles and water absorb or deplete lubricating additives, which affect engine oil performance and increase the friction and wear of engine components. Additive depletion is an interesting subject due to improvements of media filtration systems, using centrifugal or ultra-filtration systems. The most commonly asked question when using advanced filtering processes is; does the oil filter have an ability to remove additives from the oil or just remove contaminants? By finding the amount of additives that have been depleted and replenishing them can extend the engine drain intervals, reduce waste oil generation and increase the lifespan of lubricating oil.
Aims and Objectives:
- Study the effects of water in fresh and ageing oil on tribology performance.
- Finding the optimal water level in oil which does not affect engine oil performance.
- Remove any extra water over the optimal level and if water is removed how it affects the chemical analysis of oil.
- Replenish depleted additives and study the tribology performance before and after additives replenishment.
Applications and benefits:
- Reduce the effects of water contamination in engine oil which can affect physical and chemical properties of oil.
- Increase the lifespan of engine components by reduce the effect of water on the metal surfaces.
- Determine depleted additive in engine oil and replenish the additive can increase the oil change intervals especially for heavy vehicles.
- Reduce the amount of waste oil generation and the effects on environment.

Planned Impact

The impact of the Centre will be manifest itself in four ways; by the number and quality of skilled PhD graduates it produces, by the reach and significance of the research that is generated during their studies, by the contribution to the research base in tribology, and through the broader societal impact of improved machine efficiency and energy utilisation.

The number and quality of PhD graduates. iT-CDT plans, in the steady state, to graduate 12 PhD students per year. We expect these students to enter industry as research leaders or academia as RAs then lecturers. UK and EU industries are desperately short of PhD graduates, and they are in demand. We expect to have impact on UK industry with a stream of PhD graduates who will enter for example, the automotive sector (e.g. designing more fuel efficient engines), the rail sector (e.g. increasing network capacity and reducing cost through improved track and vehicle components), the oil industry (e.g. developing new lubricants for increased fuel efficiency), aerospace sector (e.g. tribology needs in jet engines), the power industries (e.g.developing and maintaining more efficient transmissions). PhD students may also commercialise technology or consultancy in the form of a spin-out activity. We have a track record of past PhD students achieving all these things. The iT-CDT plans to extend and broaden that record, will facilitate synergy across the discipline.

The transformative PhD research. During their studies, PhD students will be conducting research on an industry led project. These projects will also have elements of generic application therefore have wide impact. The students will be closely involved with both the sponsoring organisation and other industrial partners. This means that there will be a direct route for technology transfer.

Contribution to the Research Base in Tribology. The iT-CDT is a grouping of the two leading universities in tribology in the UK. It will form the largest critical mass of academics, RAs, and PhD students in the EU. A team of industrial partners will steer the research so that it is relevant and has real routes to impact. This platform will lead to a growth in the research base in tribology for the UK and will impact both industry, with improved products and processes, and academia with the supply of new technology and analytical methods.

Societal Impact. The development of new tribological processes, and engineers skilled in their conception and implementation, will have broader societal impact with machines and process that run with lower friction, higher energy efficiency and have greater durability. In the shorter term, we also plan as part of the iT-CDT for public engagement events using PhD students as the agents of delivery.


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Description Engine oils are degraded and changed before the service life of oils are consumed, the project has initial results that proved if the contamination are removed from engine oils. The oils change periods will be extended and the oils in trucks will work for longer time at same performance with less cost and less effect on the environment. So,I found that removing the contamination from used engine oil and replenishing the engine oil with additives extends the life service of engine oil.
Exploitation Route Project outcomes will be used in heavy diesel trucks applications that are consuming a huge of amount of engine oils.
Sectors Chemicals




including Industrial Biotechology


Description Parker Filtration Ltd 
Organisation Parker Hannifin Corporation
Department Parker Hannifin Plc
Country United Kingdom 
Sector Private 
PI Contribution This project is aimed to: 1. Understand the effects of contaminants on engine oils and the degradation of oils by contamination in heavy diesel engine of trucks. 2. Determine the service life of engine oils in trucks and avoiding the factors that can degrade the oils.
Collaborator Contribution The partner is supplying experimental materials, experimental methods, guidances and access to partner's laboratories.
Impact Project outputs are; 1. Understanding the effect of soot level on engine oils and the adsorption of additives by soot. 2. Determining the critical level of water in engine oils and how it effects on oil performance.
Start Year 2018
Description Presenting a poster in Mechanical Engineering PGR Poster 2020 event at University of Leeds 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact The event is aimed to develop presentation skills of project outcomes , research progress and discussion skills with academic members.
Year(s) Of Engagement Activity 2020
Description Tribology showcase event is holding annually with sponsors to discuss the outcomes of project that are running at University of Leeds. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact I presented a poster and the discussion was around the project suhc as how the work is linking to indsrutial and the benefits of these outcomes.
Year(s) Of Engagement Activity 2019,2020