SECTOR FOCUS:
TESTING
The test of time
Frank Bellgardt, OEM Relationship Manager and Senior Field Trial Supervisor, Afton Chemical Katie Richardson, Senior Customer Technical Services Manager, Afton Chemical
The ACEA 2020 Heavy Duty Oil Sequence update expected in December brings significant changes in lubricant testing – many driven by oxidation concerns.
constant pressure to drive down their total cost of ownership, the priority is delivering more performance for the same or less cost.
While there is continued focus on engine durability and fuel economy in ACEA 2020, the most stringent tests and performance limits will centre on oxidation control.
Truck engines are often operating hotter thanks to higher power output, yet must still run for longer between oil changes. Extended drain intervals must be achieved using the thinner lubricants that help to maximise fuel economy and meet emissions legislation. However, these fluids must not compromise exhaust after-treatment systems, which can be expensive to replace.
The changes relating to oxidation control come from three main sources: increased use of biodiesel, longer oil drain intervals and higher engine power density. It is to be anticipated that these trends will continue to influence lubricant performance in years to come. In many countries environmental legislation already mandates minimum levels of biodiesel in diesel fuel and the percentages are likely to keep rising. Biodiesel accumulates in oil and oxidises more easily, so it’s more likely to lead to engine deposits. With Heavy Commercial Vehicle operators under
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All this means that thinner lubricants are working at higher temperatures, for longer periods, and bound by chemical limit requirements in more recent specifications to comply with after-treatment systems. This places enormous stress on the fluid, particularly with respect to oxidation. Effective oxidation control solutions are fundamental to ensuring lubricants perform reliably over time;
particularly for trucks working under harsh conditions. Such conditions may run from heavy urban traffic to mountainous inclines, poor road quality, heavy loads and higher sulphur fuels. So what does all this mean from a testing perspective? One major change is the expected introduction of the Volvo T-13 oxidation test. The T-13 has been in the US API CK-4 specification since 2016. It’s inclusion represents a step change for ACEA. The T-13 evaluates oxidation performance by measuring oil thickening and oxidation by-products, as well as monitoring oil consumption – all of which can reduce engine protection and cleanliness. New or uprated performance demands will likely need to be satisfied within the next 12-24 months, if existing or new lubricants are to make relevant claims. More severe limits are also expected for engine test OM646LA Bio, which has an increased focus on biodiesel oxidation performance. Existing bench tests for oxidation such as Pressure
Differential Scanning Calorimetry (PDSC), which looks at how quickly oil breaks down on heating, and CEC-L109, which evaluates a fluid’s oxidation tendency with added biodiesel, will also continue to be a requirement in all new ACEA categories. Daimler also has a bench test assessing oxidation control. Considered more severe than CEC-L109, the Daimler test is run on fluids at a higher temperature and is carried out with and without biodiesel content. As cost pressures push OEMs and end-users beyond drain intervals of 150,000km and towards 200,000km, protection against oxidation will remain a priority. Through ACEA bench and engine tests, as well as real world trials in partnership with OEMs, Afton keeps a close eye on future trends. Only by looking ahead can lubricant performance truly be made to stand the harshest test of all – time.
LINK www.aftonchemical.com
Afton’s Volvo T-13 rig
LUBE MAGAZINE NO.160 DECEMBER 2020
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