It's back to minding the miles and quarts. Over the past ten years, trucking's been digesting gallons of news about motor oil. Waves of new lube formulations have been coming to market since 1998, each specifically engineered to satisfy the demanding lubrication requirements of successive federal emission rules for diesel engines.
But with no new API oil-service category in sight, both fleet owners and oil marketers can now focus squarely on what the latest oil formulation — API CJ-4 — can do not just to protect their newest (EPA '07-compliant) engines, but perhaps to cut operating costs for all their engines.
Oil company executives who spoke to Fleet Owner generally concur that many fleets are either unaware or unconvinced that the newer CJ-4 oil can allow a single, extended drain across all of a fleet's engines.
“Some fleets are continuing to use two oils [CI-4 Plus and CJ-4] due to the cost differential [at purchase],” says Mark Betner, Citgo's manager of heavy-duty products. “They're watching their pennies to be sure. But that approach can create an inventory-management issue.” He remarks the irony is that “we [in the oil industry] had heard fleets wanted one oil [for '07 and earlier engines] in the first place.
“I don't think that we as suppliers have made it clear about what CJ-4 can do,” Betner continues. “The fact is CJ-4 outperforms previous oil categories in every aspect. Millions of miles of testing show it outperforms older oil significantly.”
“Mixed fleets, with some 2007 model and newer engines combined with older engines, can be faced with a difficult choice to inventory two lubricants, CI-4 Plus, which will be more cost-effective for their older engines, and API CJ-4, which is the best oil for 2007 model and newer engines,” says Eric Olsen, staff engineer-lubricants technology team of Chevron Global Lubricants. “The engine makers are clear about their preference for API CJ-4.
“Considering what we've seen happen for passenger-car motor oils, it should not surprise anyone that heavy-duty oils are evolving in similar directions [towards longer drain cycles],” he continues. “For many years, heavy-duty diesel engines have been designed for maximum durability… as with any drain optimization program, the first source for oil recommendations should be the engine manufacturer.”
“We deal with this [extended drains] all the time,” remarks Brianne Wissel, technical adviser for commercial vehicle lubricants at ExxonMobil. “And we certainly kept that concern in mind as we researched [the move] from CI-4 Plus into CJ-4 for Mobil Delvac.
“With any extending of oil drains,” she continues, “there must be a substantial caveat though. The application must be taken into account. The equipment, duty cycle and even the climate can vary widely and all these factors must be taken into account.”
Even so, Wissel says ExxonMobil has “not seen any decrease in established drain intervals” by fleets moving to CJ-4. “Our testing, which included pre- and '07 engines to account for mixed fleets, indicated no need to change the drain interval. Nothing told us to step back and we have seen instances of CJ-4 oil allowing a longer drain on pre-'07 engines.”
Walt Silveira, North American technical manager for Shell Lubricants, reports that fleets that have converted to Rotella T, a CJ-4 oil, are “seeing great results from an oil-analysis perspective: wear rates, soot levels, cleanliness of the engine, are all under control.” He says Shell has ascertained this through its VideoCheck program that inspects engines via injector openings providing a view inside the cylinders. “This year we will see some '07 engines hitting the 500,000-mi. mark on CJ-4 and we look forward to doing actual teardowns.”
Reginald Dias, director, commercial lubricants for ConocoPhillips Lubricants, offers a very wide view of the extended-drain question that doesn't overlook the big picture. “It is inaccurate to judge the benefits of the CJ-4 quality lubricant by oil drain interval alone,” he argues. “CJ-4 is the highest quality of diesel engine oil available today, which surpasses the previous quality level in every aspect of performance and engine protection.”
Dias points out that “today most major oil marketers offer CJ-4 performance engine oils of one or more tier quality level. The premium-tier engine oils are generally formulated to meet enhanced performance metrics that exceed the minimum industry standard and provide added value and benefits to end-users. Premium-quality engine oils are designed to provide reduced engine wear, better soot handling capability, higher oil oxidation stability, extended oil drain and overall improved engine protection relative to market general products. These enhanced features result in better performance benefits in both new and old engines.
“The premium-quality lubricants generally have capability to extend engine oil drain interval beyond that which is normally recommended for the equipment,” he continues. “The extended drain capability will apply to both pre-'07 and later-model diesel engines.”
According to Citgo's Betner, CJ-4 oil clearly gives fleets the “potential to optimize oil-drain intervals past where CI-4 Plus may have taken them as long as they do it properly.” He urges fleets to “use the right tools,” meaning used-oil analysis and strict adherence to PM schedules.
Betner adds that by using CJ-4 oil, “fleets should be able to stay where they were with drains on '07” engines as well. “I think the question for mixed fleets of pre- and '07 engines is can they sustain an oil drain interval across all their engines, and the answer is most likely ‘yes’ — as long as they use oil analysis. And of course, that means pre-'07 fleets may be able to extend their existing drain intervals with CJ-4. The truth is many fleets are operating somewhat conservatively with the newer oil. That's why oil analysis remains so important. You don't want to go forward without that physical checkup.”
“CJ-4 lubricants are very robust and provide a high level of diesel engine protection,” says Paula Del Castilho, category manager of commercial transportation lubricants for PetroCanada “Of course, whenever we consider extending oil drains we know that the type of operation, load, service, maintenance and many other things can play a role. We always recommend use of a good oil analysis program to determine the right drain interval for a fleet.
“Having said that, we have found that CJ-4 oils can be used for extended drains,” she continues. “In our tests, we have achieved results as long as two or even three times the OEM recommended drain interval with our Duron E 15W-40 in pre-'07 engines on ULSD [fuel]. We're developing data in EPA '07 engines now, but we expect the same high level of performance.”
Shell's Silveira says that, depending on the customer operation, if a fleet had “extended drains using CI-4 Plus oil, the data for our Rotella T suggests they can continue that drain for both their pre- and '07 engines. With CJ-4, they can have one oil and one drain.”
That being said, Silveira notes that he finds “most large fleets stick with an oil drain tied to an established maintenance interval while smaller fleets may be more likely to extend drains so they are separate from other maintenance intervals. He says Shell will work with customers to prepare an individual cost analysis on drains.
As to how far drains may safely be extended, ConocoPhillips' Dias remarks that “as always, end users should follow the engine manufacturers' guidelines to determine the specific oil change interval for their equipment. The specific drain interval depends on the type of maintenance program, vehicle's operating conditions, load factor, exposure to ambient conditions and the quality of fuel used. Due to these variables, no single recommendation may apply to all vehicles.”
He stresses that “caution should be exercised in generalizing the drain intervals based only on oil type. The oil drain interval may vary between engines subject to very severe service and mild service, between those with high idle time and those with less idle time or the older engines without EGR and newer engines with EGR, etc.”
ExxonMobil's Wissel recommends extending drains only when good maintenance practices can be followed and oil analysis is used to keep tabs on oil performance. “Our field team does a great job of helping get a fleet to the best oil drain interval for their given operation,” she notes.
Petro Canada's Del Castilho says a fleet should be able to set the same oil drain interval for all equipment — after they review their own oil analysis data. “Again, it's important to note that the type of service plays an important role,” she states. “If a fleet puts all their new EPA '07 units in their toughest applications, and uses the older units for the easy runs, they might see a difference. In the same application, at the same severity, Duron E 15W-40 will provide very good performance throughout a fleet and allow the optimization of drain intervals.”
“Conditions leading to fuel dilution while using biodiesel may have a different impact on the oil compared to use of regular diesel,” contends Dias of ConocoPhillips. “Often, while using biodiesel, fuel dilution will result in accumulation of more contaminant in the oil due to the less volatile biodiesel material. A well monitored oil analysis program, and/or practical experience will allow oil drain to be increased in increments of thousands of miles or by many hours of operation beyond the normal drain recommendation. The specific drain interval also depends on the timing for routine maintenance decreed by other service factors. Most of ConocoPhillips customers who had previously established extended drain with CI-4 Plus oils have been able to maintain those intervals with our CJ-4 oils.”
Chevron's Olsen concurs that uncertainty about fuel quality, especially biodiesel blends, is “among the reasons to move carefully towards extended crankcase drain intervals.” But he says this caution is not new and “has always been central to our Delo Performance Advantage program, which helps reduce operating costs through use of used oil analysis to optimize change intervals with respect to the service conditions and load factors of the particular fleet.”
“Eric [Olsen] makes a great comment about the importance of oil analysis in making a decision of which lubricant is best to inventory,” says John Shepard, direct channel marketing specialist, North America Lubricants for Chevron Products Co. “We are finding that customers are now beginning to see the value in optimizing their inventory with CJ-4 [oils] based on the field performance of CJ-4 products with their 2007 and older engines.
“One of our customers who operates a mixed fleet of 2007 and older engines worked closely with our lubrication specialists to transition their entire fleet of mixed engines to CJ-4,” reports Shepard. “Using their dedicated and robust maintenance program with oil analysis they are evaluating extending their drains from 30,000 to 50,000 miles.”
ConocoPhillips' Dias notes that the ability to extend drains can “help the fleet owner and/or operator in several ways: they can prolong the vehicle service schedule by extending maintenance interval, reduce maintenance cost, reduce oil procurement cost, minimize waste oil disposal and improve their bottom line.”
The key point is that CJ-4 oil can provide extended drain capabilities to pre-'07 as well as to '07 engines so long as the intervals are established using the recognized industry practice of used-oil analysis and the fleet follows recommended PM guidelines.
Until the Environmental Protection Agency (EPA) began clamping down hard on diesel emissions in the '90s, rolling out a new API (American Petroleum Institute) oil-service classification, known as a “donut” for the circle in which its designation is inscribed on packaging, was a rare event. But over the last 10 years, oil suppliers have had to whip up new donuts quicker and quicker.
CJ-4, which is the latest API classification for heavy-duty diesel engines, is now in effect for EPA '07-compliant engines. It is backwards-compatible for use in pre-'07 engines, and all indications are it will serve as well to protect EPA '10-compliant engines.
API ultimately licenses oil companies to display service classifications such as CJ-4 on the packaging of qualified products. But it's the American Society of Testing & Materials (ASTM) committee on heavy-duty engine oil classification that sets the limits and verifies the testing used to develop each new classification.
According to the chairman of that committee, Jim McGeehan, Chevron Texaco's global manager of diesel engine oil technology, each time the need for a new oil classification is determined, the panel works to complete the spec so that oil licensed under a new API category can reach the field before engines require it.
Once the ASTM committee completes the requirements for oil to meet a new service category, the API licensing process kicks in and a new donut rolls onto the scene.