New Proposed Category 11 (PC-11) engine oils are on the way – with an expected commercial introduction date of December 2016. And fleets want to know what that will mean for their operations and what they should do to prepare.
Some PC-11 concerns were addressed during Fleet Owner’s Nov. 16 webinar, “New PC-11 engine oils: 10 things fleets need to know." Gary M. Parsons, global OEM and industry liaison manager for Chevron Oronite Company Products and Technology, and Dan A. Nyman, technical advisor/manager fuels and lubricants for Cummins Engine Company, discussed what fleets need to know about the new engine oils.
For starters, PC-11 will include two lubricant standards – CK-4 (PC-11a) and FA-4 (PC-11b) – that will eventually replace the current CJ-4. CK-4 will be fully backward compatible with CJ-4. The second option, FA-4, however, will not be interchangeable with CJ-4 oils.
Parsons explained that lubricant specifications for the next several years will be focused on total cost of ownership, with objectives for better fuel economy, extended service and durability. He added that specific drivers for the development and introduction of PC-11 include:
- Phase I truck fuel efficiency standards, which are scheduled for phase-in 2014 through 2018
- Testing obsolescence/lack of parts beyond 2016 for several tests that are part of CJ-4 qualification requirements
- Lubricant performance upgrades, such as shear stability, thermal stability and aeration
He added that CJ-4 oils are not optimized for fuel economy. However, new lubricants with lower viscosity – referred to as high-temperature/high-shear (HTHS) – will improve highway fuel economy. Compared to CJ-4, PC-11 will improve oxidation, fuel economy and oil aeration, Parsons explained.
“Unlike buying a new truck or putting aerodynamic features on a truck, oil is something that can be changed and improve the fuel efficiency of the fleet without affecting a large part of the capital cost,” he said.
So, what will PC-11 look like in the market?
For CK-4 options, which are fully backward compatible with CJ-4, commonly available viscosity grades will be:
- SAE 5W-30
- SAE 10W-30
- SAE 5W-40
- SAE 10W-40
- SAE 15W-40
For FA-4, the thinner oil film option, referred to as low HTHS and not compatible with CJ-4, typical viscosity grades will be:
- SAE 5W-30
- SAE 10W-30
That could present some confusion in the market, Parsons points out, because there will be 5W-30s and 10W-30s on both sides, but they will be different. He added many OEMs are still on the fence when it comes to low HTHS oils, and mentioned CK-4 options will be more prevalent.
Though OEMs have not yet established drain interval changes for the new oils, Parsons advised that when they do switch over, a used-oil analysis is a good way of determining appropriate oil drain intervals.
When it comes to engine design, over at Cummins, PC-11 hasn’t just been a big topic for customers, but it has been a challenge for engineers, according to Nyman. Based on lower HTHS assessment, Nyman said the better oxidation stability may lead to less cooking levels in piston cooling galleries and under crowns. He added that filtration may play a bigger role as debris size could be much larger than the oil film thickness.
“We recommend using oil analysis parameters that monitor the changes to the oil and actually precede failures,” he said, noting failures include corrosion, wear, deposits, and viscosity increase. “We have found that oxidation is the biggest player in this group.”
During a question-and-answer segment of the webinar, one attendee asked whether maintenance managers would need to buy new filters to go with the new oils.
“At this point in time, the filters that we have are good enough for it,” Nyman said. “The issue is making sure you change them with your oil. That’s the important part.”
Someone else asked if oils could be mixed during the changeover.
“If you’re going from CJ-4 to CK-4 I don’t see a problem with mixing because you’re just adding more antioxidants,” Nyman said. “If you’re changing to an FA-4, I would probably want to drain and then refill the oil itself.”
What fleets can take away is that PC-11A, introduced as API CK-4, is fully backward compatible and can be used in most applications where CH-4, CI4, CI-4PLUS and CJ-4 are currently used. Some CJ-4 oils may remain in the market after CK-4 is introduced. And fleets should look for CK-4/SN if using the oil in diesel and gasoline engines.
PC-11B, introduced as FA-4, will not be backward compatible, and fleets should use FA-4/SN on diesel and gasoline engines. Parsons said the owner’s manual or OEM should be contacted regarding use restrictions.