When the American Petroleum Institute (API) approved its latest diesel engine oil standards – API Service Categories CK-4 and FA-4 – it marked a significant milestone in the development of diesel engine oils. API had developed two new standards, rather than one, to meet new emissions and fuel efficiency regulations and provide improved protection for current and future diesel engines.
API (www.api.org) is the only national trade association that represents all aspects of America’s oil and natural gas industry.
“These new service categories, which became effective on December 1, 2016, improved upon existing API standards by providing enhanced protection against oil oxidation, engine wear, particulate filter blocking, piston deposits and degradation of low- and high-temperature properties,” explains Kevin Ferrick, senior manager, engine oil licensing, API.
“The new engine oil specifications were needed for heavy duty diesel engines because these engines have changed significantly since API introduced its last diesel engine oil specification, CJ-4, in 2006.”
Today’s engines run more efficiently, generate more power and feature different hardware, he notes. For example, many use high pressure, common-rail injection systems that are now widely used to improve combustion efficiency. In addition, advanced turbocharger technology increases power output, and the use of diesel particulate filters and selective catalytic reduction decreases or prevents emissions of harmful oxides of nitrogen and particulate matter.
New Emissions Regulations
New U.S. EPA and NHTSA emission legislation for diesel-powered commercial transport vehicles to take effect this year requires significant improvements in fuel consumption that will help to reduce carbon dioxide emissions. The fuel consumption improvements cover different vehicle classes, types and sizes, in addition to specific improvements required for medium and heavy duty engines.
“Changes in engine technology require changes in oil performance,” API’s Ferrick says. “Oils now have to lubricate ever more effectively, while also cooling, cleaning and protecting these new engine designs effectively. Lower viscosity oils, such as 10W-30, are expected to be one tool used to help deliver fuel economy savings while still providing the protection and durability needed.
“The new generation of high-performing CK-4 and FA-4 diesel engine oils provide engine manufacturers with the protection they need as they design cleaner, more fuel-efficient diesel engines.”
Fuel Economy Improvements
Lower viscosity oils are known to help increase fuel efficiency, which in turn helps to reduce greenhouse gas (GHG) emissions.
Ferrick of API notes that according to the Fuel Efficiency Confidence Report, published last year, “Class 8 over-the-road fleets can realistically expect fuel savings in the range of 0.5 percent to 1.5 percent by switching from 15W-40 to 5W- and 10W-30 CJ-4 or CK-4 engine oil. The savings from switching to the fuel-efficient FA-4 oil can be expected to add a further 0.4 percent to 0.7 percent of increased fuel efficiency.”
Increases in fuel economy can result in significant reductions in fuel consumption and carbon dioxide emissions, he adds. The reduction in CO2 output arises from the engine’s running more efficiently, and consequently putting less CO2 into the environment.
Oil Selection
Many truck and off-highway equipment manufacturers that recommended API-licensed CJ-4 engine oils are beginning to recommend API CK-4 oils to better protect their diesel engines, reports API’s Ferrick. In contrast, API FA-4 oils have been designed to protect diesel engines introduced in the 2017 model year.
API recommends that technicians and consumers check with the manufacturer of their engine to determine the correct oil to use. API CK-4 and FA-4 are now appearing in the API Service Symbol “Donut.”
“Most truck and equipment manufacturers that recommended API-licensed CJ-4 engine oils are beginning to recommend owners start using licensed API CK-4 oils,” he says. “API CK-4 oils will provide enhanced protection for today’s diesel engines.”
CK-4 oils are also recommended for use in engines meeting Tier 4 non-road exhaust emission standards.
API FA-4 oils, however, are different. “The FA-4 standard describes certain lower viscosity oils specifically formulated for use in select high-speed, four-stroke, cycle on-highway diesel engines designed to meet 2017 model year on-highway GHG emission standards. Some manufacturers are now recommending the oils for their 2017 model year engines.”
For more information about the new API CK-4 and FA-4 service categories, visit www.NewDieselOil.com.
