Tips for interpreting used oil analysis data

by Darryl Purificati, Sr. Technical Advisor, OEM/Automotive at HollyFrontier Lubricants & Specialties, which includes the Petro-Canada Lubricants brand

Conducting used oil analysis and interpreting the reports for a fleet of heavy-duty vehicles can be seen by some fleet managers as an extra or add-on to a maintenance program, especially if the trucks in the fleet are leased and therefore covered by the warranty.

However, used oil analysis data can be extremely valuable for fleet owners and operators looking to find efficiencies, uncover maintenance issues before they become too expensive or serious and secure cost savings. By incorporating used oil analysis into a proactive maintenance program, fleets can evaluate results and trends on an ongoing basis which allows for a better-informed maintenance schedule. For example, regular used oil analysis offers the potential to safely extend oil drain intervals*, which provides fleet owners with an opportunity to reduce maintenance costs and keep their vehicles on the road for longer between scheduled maintenance.

Interpreting the results

For fleet managers that may not be confident in interpreting used oil analysis data, we always recommend seeking advice from a lubricant expert, like a technical service advisor, who can use their expert insight and experience to provide analysis and highlight trends and changes in the report’s findings. They can evaluate the trends that have developed over time and identify any anomalies as well as provide recommendations for maintenance and, when possible, extending oil drain intervals.

Lubricant experts can also support fleet owners and operators in learning how to identify trends in used oil analysis data so that they can become more confident interpreting and understanding their fleet’s data. An important part of this process is being aware that oil sampling platforms often do not consider the wear or chemical limits of each engine Original Equipment Manufacturer (OEM), so it’s important that fleets are aware of the engine thresholds for their fleet – particularly if operating a mixed fleet – when interpreting the data.

When first reviewing a used oil analysis report it is important to look at many of the key indicators of the oil’s condition, such as the base number (BN), acid number (AN), viscosity, oxidation, percentage of soot and fuel dilution as well as wear metals.

There are several common anomalies to look out for when reading the results of a used oil analysis report. If a report shows that coolant or glycol is present in the engine oil, it could be the result of a failing EGR cooler seal, which would require immediate attention from a mechanic and potentially an oil change. The presence of silicon, potassium or sodium can also be an early warning sign that this is taking place so are important properties to monitor.

Increases in iron and aluminium can be indicators of a failing camshaft, coolant leak attacking the liners, or the engine requiring mechanical adjustment. Spotting these changes early in a used oil analysis report can result in maintenance that is both less disruptive and less costly.

One of the most critical anomalies to look for is the presence of unburnt fuel combined with an increase in common wear metals such as iron, aluminium, lead and copper, as these are indicators that the protection of vital engine components may be compromised. If this occurs, expert lubricant advice and mechanical expertise should be sought immediately to help resolve the issues.

The latest digital diagnostic tools

 Digital diagnostic tools such as HollyFrontier Lubricants & Specialties’ LUBE 360™ Oil Diagnostics, can allow used oil analysis samples and data results to be viewed from tablets and mobile devices, allowing immediate access to the latest insight, 24/7. For asset managers, the easy-to-use dashboard graphs can help to prioritize critical results and detect abnormalities within the data, meaning contamination is recognized earlier and necessary steps such as filtration can be taken to help maintain oil cleanliness. Utilizing digital oil diagnostics can help fleets stay one step ahead by using the latest technology to proactively track where maintenance is needed and make predictions about where it will be needed in the future.

For fleet owners and operators looking to make real cost efficiencies in their maintenance schedule, incorporating a robust used oil analysis program and becoming confident interpreting used oil analysis results should be a priority. Conducting used oil analysis as part of a proactive maintenance program can offer a wide range of benefits for fleets, including reduced maintenance costs and less unplanned downtime, as well as the potential to extend oil drain intervals safely.

*Extending drain intervals should always be undertaken in conjunction with an oil analysis program.


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