TECH TALK / Post date: 1 March 2015
The development phase of the new PC-11 engine oil performance category continues to progress. However, due to delays in test development and validation, formal introduction of PC-11 may be delayed until March 2017, although this date could potentially shift back to December 2016.
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 category 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 valvetrain 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. 2017 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 the oil stays in grade during use.
There are two new engine tests which will be part of PC-11, the Mack T-13, and a Caterpillar aeration test. Matrix evaluations of these tests have now been completed and the data is being analyzed by statisticians to determine the pass/fail limits of the tests.
Castrol’s Global Technology Team continues to work closely with its additive technology partners to help refine and shape the next generation of high-performance HD lubricants.