In order to meet the goals for more fuel-efficient engines and fewer emissions, as required by the greenhouse gas (GHG) emissions reduction regulations, many next-generation heavy duty diesel engines will run at higher operating temperatures. This, say oil company officials, will require changes in engine oil composition so these new engines can withstand more heat without sacrificing engine protection.
The oil industry is developing a new category of lower-viscosity diesel engine oils as part of the upcoming Proposed Category 11 (PC-11) oils. The officials say these new heavy duty engine oils, which will surpass current CJ-4 oil technology, will provide a number of benefits, including:
- Improved fuel economy and reduced CO2 emissions.
- Enhanced engine protection against wear, oxidation, aeration and deposit buildup.
- Helping to maintain protection of emission systems with diesel particulate filters and selective catalytic reduction.
- Better performance under high-temperature engine operation.
The new PC-11 oils are due in early 2017.
TWO TYPES
There will be two subcategories of PC-11 oils: PC-11A and PC-11B.
PC-11A oils will be a direct replacement (backward compatible) for the heavy duty diesel engine oils being used now in older and newer engines, oil company officials explain. PC-11A oils will be available in the same viscosity grades and oil types – conventional, full synthetic and synthetic blend.
The PC-11B oils, which will be offered in lower viscosity grades, are designed to help maximize fuel economy with no compromise in durability, they say. These oils may have limited backward compatibility and will typically only be recommended by OEMs for use in model year 2017 diesel engines.
AN INDUSTRY FIRST
PC-11 will be the first heavy duty engine oil category to feature two distinct levels of high-temperature, high-shear (HTHS) viscosity, in addition to the standard SAE grade nomenclature commonly used today – for example, 10W-30, note oil company officials.
PC-11A oils are referred to as high HTHS viscosity engine oils.
PC-11B oils are known as low HTHS oils. These oils are being designed to provide fuel economy above and beyond current CJ-4 and PC-11A oils through the use of thinner viscosity fluids.
