Condition-based oil changes: Save money and protect the environment

Protecting the climate and saving energy and resources are topics that are right on trend. Almost every company is working hard to reduce its carbon footprint. Meanwhile, returning a profit is becoming increasingly difficult, with manufacturing costs having only gone up in recent months. Savings are on everyone’s agenda wherever possible, and all operational processes are being put in the spotlight. However, too little attention is often paid to lubricants. Even if higher-quality premium lubricants are used for the first time, they are often replaced far too early due to the fact that they have always been changed at fixed intervals or because it has been stipulated by the oil supplier.

When monitored using professional oil analysis, however, lubricants can be changed based on their actual condition. At the same time, the systems’ operational safety is ensured as the analyses also detect contaminants and any wear processes. This means the cost-effective analyses pay for themselves in a short time.

If oils are changed based on their condition instead of at fixed intervals, you’ll be doing your bit for the environment. Fewer oil changes mean the following:

* Less need for fresh oil
* Less oil extraction and crude oil transport
* Fewer energy-intensive refinery processes
* Less transport of fresh and used oils
* Less reprocessing or disposal of used oils

The bottom line is that fewer oil changes reduce the formation of CO2 . The production and disposal of lubricants alone creates CO2 emissions of approximately 1.5kg CO2 per litre of oil*. However, fewer unnecessary oil changes also have an additional effect that should not be underestimated, particularly in today’s climate – they have a positive effect on the cost balance sheet. I illustrate the amounts involved using two practical examples.

3MW wind turbine - Main Gearbox

The components in a wind turbine are hard to access. Inspections, maintenance work and oil changes take place at high altitudes, and components failing result in long interruptions to operations. Changing the oil just once costs several thousand euros.

Components in a wind turbine require a range of different lubrication oils, greases and coolants. To clarify the cost-benefit balance of condition-dependent oil changes, which are accompanied by oil analyses, only the 1,100 litres of synthetic gear oil that lubricate the planetary gear of a 3MW system have been taken into account in the example.

Analyses of the gear oil carried out every six months in the OELCHECK laboratory in Brannenburg, Germany have shown that the gear oil’s service life can be doubled from 30,000 operating hours (5-6 years) to 60,000 operating hours (10-12 years).

Goods vehicles – Euro 6D six-cylinder diesel engine

A well-known German freight forwarder is leading the way in reducing their CO2 emissions. They have around 150 trucks on their books that run solely on biodiesel (B100), which reduces CO2 emissions by around 80% compared to running on diesel (B7). With an average consumption of 33 liters per 100 kilometers and a mileage of around 120,000 kilometers per year, each heavy goods vehicle emits 70 tonnes less CO2 each year.

Unfortunately, there’s a catch. Several years of findings relating to running engines on pure, non-esterified rapeseed oil indicate that engine manufacturers still stipulate that B100 engine oils should be changed at shorter intervals. This should eliminate the risk of increased fuel entry when running on B100 and of any resulting subsequent damage to the engine. To meet the engine manufacturer’s warranty conditions as defined in the lease contracts, the freight forwarder had to shorten the oil change intervals from the usual 120,000 kilometers to 30,000 kilometers. Shortening the intervals led the cost accounts for oil changes and the CO2 balance sheet to soar due to the following:

* The amount of used and fresh oil increased fourfold.
* The costs for changing the oil and the associated downtime quadrupled.
* Additional, avoidable CO2 emissions generated during the production, transport, and disposal of engine oils.

Based on the initial situation, the freight forwarder and OELCHECK launched a trial in collaboration with the truck manufacturer.


As part of the test, the engine oils in the four trucks with Euro 6D six-cylinder diesel engines were analysed in the OELCHECK lab every 5,000 kilometers. The limit values of the individual parameters were agreed with the vehicle manufacturer in advance. In this light, the following values came under particular scrutiny in the lab: any B100 fuel entry into the engine oils, a change in viscosity, oil oxidation and wear parameters. The short analysis intervals of 5,000 kilometers acted as a safeguard so we could intervene at short notice should serious deviations be detected and therefore avoid significant damage to the engines. In all four trucks, the engine oils reached the 30,000-kilometre milestone – the point at which an oil change would otherwise have been due, according to the manufacturer’s instructions – without presenting any issues. The oil quality also returned good results at that point. The oil showed signs of ageing in the following 30,000 kilometers (up to 60,000 kilometers). However, this proved to be within scope. As expected, the fuel content in the oil increased throughout the test. The fuel entry was only proven to be moderate in all four vehicles observed, and the viscosity did not change as a result. The limit values agreed with the manufacturer were never reached, while wear metals could only be detected in low concentrations.

The analysis data showed that the vehicles’ oil should be changed every 90,000 kilometers. To be on the safe side, however, the vehicle manufacturer involved in the test approved extended oil service intervals of up to 65,000 kilometers based on the data established for the haulage vehicles used in long-haul transport.

The freight forwarder, which runs over 150 vehicles on biodiesel (B100), would save over 75,000 € in engine oil costs per year due to tripling the oil change intervals as determined by the oil analyses. In addition to the cheaper biodiesel costs, the forwarder would secure a much more favourable cost structure in the much-discussed freight forwarding industry as well as a better CO2 balance.

About the Author

Mr. Stefan Mitterer, an esteemed tribologist and Business Director at OELCHECK GmbH, leads the Technology, Service & Sales Department. With expertise in lubricant and fuel analysis, he advocates for sustainable practices, emphasizing the importance of condition-based oil changes. His contributions drive cost savings and reduce the carbon footprint in industrial operations. By promoting professional oil analysis for extended lubricant lifespan, he champions environmental conservation and resource optimization.
For further information, reach out to Mr. Stefan Mitterer at stm@oelcheck.de

Stefan Mitterer
Business Director of the Technology, Service & Sales Department | OELCHECK GmbH