Separate Oils for Newer and Older Engines Being Developed for Heavy-Duty Trucks
This story appears in the March 30 print edition of Transport Topics.
The next generation of engine oil for diesel-powered trucks will offer commercial buyers increased variety, with separate blends for newer and older engines and a subcategory to reflect some fleets’ shift to lighter oils, said oil and engine manufacturers.
But with research ongoing into the demands that will be placed on these new oils, development is taking time.
The new oils, the performance standard for which is titled PC-11, are being created through a painstaking, collaborative effort involving the American Petroleum Institute, the American Chemistry Council — which represents additive manufacturers — and the Truck and Engine Manufacturers Association.
The PC-11 standard will represent the first time that the heavy-duty diesel oil category will be divided into two subcategories. The oils will have the same performance specifications but different viscosity requirements — one similar to 15W-40 oil for legacy vehicles and one for thinner, lighter grades.
The current standard, CJ-4, has been in use since 2006 and was created for engines built to comply with federal emissions standards that took effect with 2007 model-year engines. A second round of federal emissions regulations took effect in 2010, and brought with it the arrival of selective catalytic reduction emissions systems on diesel engines.
In 2011, EMA asked API to create the PC-11 category, asserting that newer engines tuned to meet the stricter regulations tend to run hotter than older models. The changes to the oil require a different type of lubricant as well as a different testing process than is required for CJ-4, said Roger Gault, EMA’s vice president of regulatory activities.
The new oils will be able handle higher temperatures caused by reactions with oxygen that can cause oil to become acidic and more corrosive, said Dan Arcy, global OEM technical manager for Shell Lubricants.
The heavier subcategory is known during development as PC-11A and likely will be known as CK-4 when licenses are granted, said Kevin Ferrick, manager of API’s engine oil program. The lighter subcategory is being called PC-11B during development and likely will be known as FA-4 after licensing, he said.
The creation of the lighter subcategory reflects a growing preference among fleets for lighter 10W-30 and 5W-30 oils rather than the still-dominant 15W-40. Reasons often cited for the switch include better fuel economy and easier startups in colder temperatures, Arcy said.
“A lot of motor carriers are doing it,” he said of the migration toward lighter oils. “We’re seeing a switch there. In fact, 10-30s like that now are the predominant oil for factory fill across all truck manufacturers.”
But before PC-11 has a chance at becoming a factory-fill option, a lot of testing must be done, engine makers said.
Greg Braziunas, Daimler Trucks North America’s manager for engineering mechanics, said his company is “doing a significant amount of testing with our older model engines to understand how backwards compatible the new oil can be.”
Trevor Lokie, Peterbilt product planning manager for powertrains, said his company “is working closely with its oil supplier partners to ensure our lineup of engine offerings will operate at peak performance with the PC-11 diesel engine oils.”
Roy Horton, director of product marketing for Mack Trucks, said the company is “testing oils through our T13 engine oil test. What we’ve found so far is that many of today’s oils will have to be reformulated to pass the T13 test as part of PC-11.”
Dan Nylan, technical advisor for chemical technology and lubricants performance testing at engine manufacturer Cummins Inc., said that the development process has not reached the point where actual oils are being tested on its engines.
“We are working with additive and oil companies to test what they think will be the final formulations,” he said. “We are not far enough along in our testing to make definitive conclusions, but it looks promising.”
And those additives will be an important ingredient in the new oils, said Gerald Shaw, product line manager of the Americas at Chevron Oronite, which makes additives for lubricants and fuels. Shaw said the shift to lower viscosity grades means additives probably will contain friction modifiers, new and improved detergents, and anti-wear and anti-oxidant components. He expects additives to be “rebalanced” to improve fuel economy and prevent wear.
Steve Haffner, North America crankcase market manager for petroleum-additive manufacturer Infineum USA, does not expect significant changes to the additives used in PC-11A, the heavier category, because it must be backward compatible with older engines. He said additives for the two subcategories could be similar, but as viscosities decrease and needs diverge, the additive mix could change.
“Infineum expects to see significant growth in demand for SAE 10W-30 as well as increased demand for both SAE 5W-30 and 5W-40,” he said. “This will all be at the expense of the SAE 15W-40 viscosity grade.”
But oil manufacturers are expecting PC-11 blends to improve fuel economy.
Barnaby Ngai, category portfolio manager for transportation oils for Petro-Canada Lubricants, said his company’s DURON-E UHP 5W-30 has increased fuel economy up to 4% in tests comparing it with the company’s DURON-E 15W-40 oil while delivering twice the engine protection. Petro Canada is running tests with a fleet hauling 140,000-pound loads in extreme Canadian conditions, Ngai said.
Arcy said Shell’s 10W-30 has demonstrated a 1.6% improvement in fuel economy over its 15W-40, with no differences in durability. Shell Rotella already has run more than 20 million miles on more than 200 trucks.
But final development of the oils still is under way.
Early on, an industry evaluation team chaired by Arcy determined that EMA’s original request for new oil standards was warranted. After that determination, a second phase began in December 2011 with the creation of a development team, also chaired by Arcy. The group has been meeting regularly and examining the oil tests to make sure they are reproducible and repeatable.
Ferrick said creating the testing has been the most challenging aspect of the process. In the next phase, pass-fail limits will be created that manufacturers will use to refine their oils.
Ferrick expects no change in oil volatility requirements, nor are there expected to be major changes in the “doughnut” that appears on the back of motor oil containers describing the API certification. “We’ll run it very similar. It will be exactly how companies license today,” he said.
For now, oil and additive manufacturers, engine makers and API have at least agreed on one thing: a working date of March 1, 2017, for final licensing of the oils. However, Ferrick said planners are hoping to issue licenses as early as the fourth quarter of 2016 if things go well. Ferrick said oils can appear on shelves the day they are licensed by API.
But that likely will not happen any earlier than forecast, Gault said.
“People should not be expecting to see this on their shelves anytime soon,” he said. “It will be coming, but it won’t be coming in 2015. It may not be coming in 2016, and if it does come in 2016, it will be very late in the year.”
Meantime, information is available for fleets. Shell Rotella, for one, has introduced a website, WhatisPC11.com, to explain the process.
The change may be coming slow, but it is coming, Ngai said.
“Basically, come PC-11 we’re going to have to likely reformulate, remarket and relaunch our entire product line,” he said.
