TECH TALK / Post date: 1 September 2014
The development phase of the new PC-11 engine oil performance category 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 (PC-11a), and 2) a low HTHS viscosity category for the new fuel efficient, low carbon dioxide emission engines coming in 2016 (PC-11b).
PC-11 will be the first HD 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 (i.e. 15W-40, 10W-30 etc.).
The HTHS viscosity of oil is measured under high temperatures and shear rates, which predict its performance in the engine valve train and camshaft area. 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 tighter shear limits to ensure that oils stay in grade during use.
The development phase of the new engine tests proposed for PC-11 is essentially complete and the decision whether to include the new tests in the category has been made. There are two new engine tests that will be part of PC-11, the Mack T-13, and a Caterpillar aeration test. There is a third piston scuffing test still under development by Detroit (Diesel) and, as of now, will not be part of PC-11, but may be included later this year.
Now that 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, and generate rigorous statistical data which will form the basis of the end specifications. This matrix testing was expected to commence earlier this year, but has been delayed.
Due to the delays in test development and validation, formal introduction of PC-11 oils may be delayed by 6-9 months from the initial target of January 2016.
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.