TECH TALK / Post date: 1 November 2013
The development phase of the new diesel engine oil performance category (PC-11) is continues to progress. As a refresher, the next generation of HD engine oils will have two subcategories: 1) a standard HTHS 15W-40, 10W-30, or 5W-30 for older engines, and 2) a low HTHS viscosity category for the new fuel efficient, low carbon dioxide emission engines coming in 2016.
PC-11 will be the first HD oil category to feature two distinct levels of high temperature including high shear (HTHS) viscosity in addition to the standard SAE grade nomenclature commonly used today (i.e. 15W-40, 10W-30, etc.). An oil’s HTHS viscosity is measured under high temperatures and shear rates, which can predict the oil’s performance in the engine valve train and camshaft areas.
Oil viscosity is a significant contributor to the fuel efficiency of an engine and, as with other viscosity numbers, lower HTHS viscosities equate to better fuel economy. The 2017 model year engines will allow the use of low HTHS 5W-30 and 10W-30 HD engine oils for both factory and service fill. Additionally, PC-11 will feature several new performance attributes including better oxidation stability, and improved biodiesel compatibility.
The development phase of the new engine tests proposed for PC-11 is almost complete and the decision whether to include the new tests in the category will be decided upon in January. Once the decision has been made to include the new tests, a matrix of runs will be performed at a number of locations to validate the results. This will generate rigorous statistical data that will form the basis of the end specifications. This matrix testing is expected to commence in early 2014.
Castrol’s Global Technology Team continues to work closely with our additive technology partners to help refine and shape the next generation of high-performance heavy duty lubricants.