SINGAPORE – Engine oils in Asia tend to lag behind oils from Europe and the Americas in their ability to prevent deposits around piston ring belts, while Asian and European oils lag those from the Americas in terms of fuel efficiency.
Those were some of the conclusions shared by U.S. test-publishing company Institute of Materials at the Fuels and Lubes Asia Conference here this month. Jonathan Evans, vice president of technical development at IOM sister company Savant Group, said results also show that a significant portion of oils in any market may not provide the performance that they should.
From analysis of these five bench tests, it is clear that the overall quality of marketed oils is improving as more stringent specifications and guidelines are implemented, Evans said. However, there are some concerns.
IOM has been collecting and testing engine oils from the marketplace since 1984. It now collects approximately 650 passenger car and heavy-duty engine oils each year, including 250 from the Asia-Pacific region. The company, which is based in Midland, Michigan, submits every oil to more than 30 tests run on bench equipment in selected laboratories.
In his March 6 presentation at Fuels and Lubes, Evans shared aggregated results from five tests over the past six years. IOM measured ability to avoid piston ring belt deposits using the TEOST MHT test, Evans said, explaining that deposits around the piston ring belt are particularly problematic because they interfere with the engine oils primary task of lubricating the cylinder walls.
According to IOM, 82 percent of oils collected from the Americas last year generated 35 milligrams or less of deposits on the TEOST MHT test, a requirement of both API SM and SN specifications for engine oils used in gasoline-powered cars. (Evans noted that not all of the collected oils claimed to meet those specs.) By comparison, 77 percent of European oils and 59 percent of those collected from Asia-Pacific met the 35-mg standard. The regions had the same rankings for piston ring belt deposits – Americas first, Europe second and Asia-Pacific third – in every year since 2008. Results for all three regions have improved since 2008, when only 40 percent of Asia-Pacific oils generated 35 mg or less.
IOM scores an oils contribution to fuel efficiency using an index that divides the power loss to viscous friction at several key sites throughout an engine by the high shear rate viscosity at each of those sites.
The Viscosity-Dependent Fuel Efficiency Index data indicates thatoils collected inEU andAsia-Pacific are not asfuel efficient asoils collected in the Americas, Evans said.
As groups, oils from both Europe and Asia-Pacific have become less susceptible since 2010 to gel in cold weather, and their performance was comparable to oils from the Americas in 2013. The regions also had similar scores for ability to prevent deposits in turbo-chargers.