PC-12 Appears on Horizon

North Americas auto and oil industries could begin work as early as next year on their next heavy-duty engine oil category, aiming to adopt PC-12 by 2027, an engine industry official told the ASTM D02 meeting last week in Atlanta.

During a joint session with the ASTM Heavy Duty Engine Oil Classification Panel and the American Petroleum Institutes Diesel Engine Oil Advisory Panel, Roger Gault, of the Engine Manufacturers Association, said the timeline for PC-12 will be driven by regulations on emissions of greenhouse gases.

The federal government has adopted limits for the next three stages of GHG emission reductions, and California is considering more stringent requirements on an accelerated timeline.

Gault commented on a possible timeline and pointed to how engine oil formulations would change to meet the needs of the engine manufacturers. The next stage of GHG limits will be in force in 2021, and Gault suggested they could be met without a new heavy-duty oil category, simply through increased use of API FA-4 oils, which have fuel economy benefits.

Further reductions are scheduled for 2024, but Gault again suggested they could be met without an engine oil upgrade, through improvements in engine and vehicle design. Those design changes might require lubricant performance improvements, but its not clear what form those could take, he added.

GHG levels in 2027 may force creation of PC-12, a new category. Gault suggested that the heavy-duty engine oil formulation chemistry would aim to deal with higher engine operating temperatures and offer improved wear protection. Meanwhile, California is developing regulations for extended warranties along with tighter nitrogen oxide limits. This could change, but discussions are ongoing.

Work could begin in the next one to two years on a possible PC-12 program, according to Gault. The PC-11 heavy-duty engine oil category was first proposed in 2011 and was introduced in 2017. The API process as outlined under API 1509 requires that a technical demonstration of the proposed tests take about one year to complete. This leads to the setting of the new category limits, followed by a one-year waiting period, which allows oil marketers to get products tested and ready for registration. Assuming that test development and proposed limits take four to five years, PC-12 development could get off the ground by 2020 or 2021.

In the meantime, API CK-4 is well entrenched in the North American market, which has a large percentage of the over 1,000 API licenses granted globally. FA-4 is also primarily a North America product, but only about 100 API licenses have been granted. FA-4 will likely continue to gain more acceptance in the market. Currently, only Daimler NA is recommending it for their 2010 and later on-highway engines and uses it for factory fill. Other engine builders recommend FA-4 only in certain circumstances.

The average age of heavy-duty engines in the field is over 14 years, and many of the players involved want new engine oil specifications to continue to be backwards compatible with precious specs. That means oils with high temperature, high shear rate viscosities of at least 3.5 centiPoise, such as SAE 15W-40, will continue to be a major viscosity grade in any new category. To gain more fuel economy benefits, API FA-4 requires HTHS viscosity of 2.9 to 3.2 cP, but as a result it is not backwards compatible.