In 2010, the National Highway Traffic Safety Administration (NHTSA) announced regulations designed to reduce the level of greenhouse gas (GHG) emissions and mandate fuel economy improvements for medium and heavy-duty engines and vehicles.
To be phased in between 2014 to 2018, the new regulations would impose different fuel-efficiency targets based on the size and weight of vehicle types. Vehicles impacted include combination tractor and trailers; pickup trucks, buses, vans and vocational service vehicles.
To address engine oil requirements of vehicles designed to meet the NHTSA standards, the Engine Manufacturers Association (EMA) made a request for the American Petroleum Institute (API) to develop a new commercial engine oil performance category. That new category has been dubbed Proposed Category 11, or PC-11 for short. The current commercial engine oil performance category, API CJ-4 (once known as PC-10), was first made available in October 2006. It will have been in the market for 10 years by the time PC-11 is released. API CJ-4 and earlier API performance categories were created to address improved engine durability and the needs of technologies introduced to reduce exhaust emissions. Diesel engine oil changes to address improved fuel economy are a new dimension.
The official category name for the new oil (similar to CJ-4) will be determined prior to its actual release. The first engine oils meeting PC-11 will be licensed under the new category name March 1, 2017.
Besides addressing fuel economy and GHG emissions, the EMA wants PC-11 to define improvements in oxidation stability and shear stability, resistance to aeration and use of biodiesel fuel.
To address the issue of fuel economy, low viscosity, fuel efficient, engine oils will be used. Currently, the vast majority of the U.S. market uses SAE 15W-40 oils for diesel engines, but this is likely to change over time. In fact, we are currently seeing an increased use of SAE 10W-30 oils.
It is important to note that NHTSA regulations designed to reduce GHG emissions and mandate fuel economy improvements only apply to on-highway trucks, not off-highway vehicles. This opens the door for the creation of two different PC-11 oils; one to meet evolving market needs and a second to provide a backwards compatibility in higher viscosity grades, like SAE 15W-40s. If the new category is split into two parts, it will be a first in the history of heavy-duty engine oil category development that this has happened.
The new category will continue to support SAE 15W-40 oils, which are expected to remain critical to both on-highway and off-highway markets. These oils have proven to provide great engine durability over time.
Content originally published by Delo, a Chevron brand.