Time to choose: One oil or two

Fleets must decide whether they are going to use CJ-4 in all equipment next year - or just in trucks with 2007 engines

On the surface, it seems like a simple decision to make: Do we go with one oil or two next year? The '07-compliant low-emission engines need the new CJ-4 engine oil in order to preserve the integrity of their exhaust aftertreatment systems, which play a key role in reducing engine emissions sufficiently to meet EPA's '07 standards. Specifically, this includes a 50% reduction in oxides of nitrogen (NOx) and 90% reduction in particulate matter (PM). While CJ-4 oil can also be used in pre-'07 engines, it's not necessary.

In the first scenario, a fleet would use CJ-4 in all its vehicles, whether they were spec'd with '07 engines or not. In the second, a fleet would use CJ-4 only in those vehicles with '07 engines, and use CI-4 and CI-4 Plus in everything else.

In reality, however, it's a little more complicated. First, since CJ-4 will cost anywhere from 10% to 30% more than its CI-4 counterparts, fleets switching over completely to CJ-4 will take a sizable hit to the wallet. That seems to make sticking with two oils a better strategy. Yet there are costs and risks associated with that decision as well.

For a fleet that performs all of its own preventive maintenance, stocking two oils rather than one is more costly. And if a maintenance technician mistakenly re-fills an '07 engine with CI-4 oil, things really start to go downhill. The aftertreatment system, especially the sensitive diesel particulate filter (DPF), could be damaged, possibly invalidating the '07 engine warranty.


According to Doug Pond, commercial vehicle lubricants product advisor for ExxonMobil, warranty invalidation is the biggest — and most costly — risk of embarking on a two-oil strategy. “Let's be clear on this. Using CI-4 in an '07 engine does not mean the engine is going to crater right away on you,” he says. “It will have negative effects, such as plugging up the DPF and probably lowering fuel efficiency. But the real risk here is that the engine OEM can invalidate your warranty. At the extra cost fleets are going to pay for these engines, they'll have too much invested to risk losing their warranty coverage.”

Most lubricant makers think fleets should switch over completely to CJ-4 for '07 and pre-'07 engines next year. Although such a move would be costly for fleets, lubricant suppliers say there are several practical advantages to this one-oil strategy.

“CJ-4 is going to cover everything CI-4 Plus does…[it will] probably do a better job than the previous oil classification,” says Mark Betner, manager of heavy-duty products for Citgo Petroleum. “There will be an increase in cost and some won't pay it if they don't have any '07 engines in their fleet. But the new oil will do better for all engines, '07 and pre-'07 engines alike.”

“CJ-4 is the best choice; it's the highest performing engine oil you can get,” adds Dan Arcy, technical marketing manager for Shell Lubricants. “You get the best level of wear protection, deposit control and soot handling — even if don't have an '07 engine. It simply protects the engine better.”

While Arcy concedes the benefits of using higher-performance oil can't easily be converted into dollars-and-cents savings, he's confident you'll see tangible benefits from oil that helps reduce engine wear by 30%.

“If you get less wear, you can assume you'll get longer life for your engine,” he says. “That translates into longer service intervals, less maintenance over its life cycle, and perhaps extends your trade-in cycle.”

According to Mike Dargento, global manager of commercial sector brand oils for Chevron Corp., there's no question that fleets will benefit from using CJ-4 in older engines, although whether it will be dramatically better is not clear. “When you add in the fact that fleets get good performance with older oil products, there's not an incentive to switch unless they have to,” he points out.

“The economy of trucking is such that fleets must watch every penny. However, simplicity of management is another key to cost control,” adds Citgo's Betner. “It simply costs more to stock two oils. [Yet] fleets might be able to get longer drain intervals with the new oil [because] it's more robust than the previous category.”


Context is also important in understanding the potential of CJ-4. Betner says that in the past, conventional wisdom was “the higher the better” in terms of an oil's total base number (TBN). “We've had to drop the TBN in CJ-4 to reduce ash-causing materials. That looks like a decrease in protection,” he points out. “But in reality it's not, because the sulfur content in diesel fuel is much lower now.” Less sulfur in fuel means less degradation of engine oil, allowing it to last longer.

ExxonMobil's Pond concurs. “Our research shows that using CJ-4 in either '07 or pre-'07 engines in combination with 15-ppm ultra-low-sulfur diesel (ULSD) fuel can result in longer drain intervals,” he explains. “TBN retention is now more important than overall TBN. Our CJ-4 oil has a TBN of 10.5…compared to the 10 to 13 TBN seen in CI-4 blends. But the key is CJ-4 retains that TBN for a longer time.”

Despite the benefits of CJ-4, its higher cost may tempt many fleets to adopt a two-oil strategy. According to Citgo's Betner, “Even for larger fleets, maybe [only] 5% to 10% of their trucks are going to have '07 engines next year. Why pay a penalty for the 96% of the fleet using older engines?”

If you consider only the purchase price of the oil, stocking two is less expensive. If you look at the big picture, however, it's not that simple. “You're talking [about] installing a second bulk tank or extra drums, dedicating more precious maintenance real estate to oil storage, and potential confusion for technicians,” Betner says.

“When I think of a large fleet with multiple maintenance facilities, say six to ten around the country, those costs start to up,” adds Shell's Arcy.

“At a minimum, you'll also need to color-code or ID your '07 trucks somehow to make sure technicians us the correct oil,” he continues. “That's the real concern: CI-4 getting into an '07 engine.”

“It's also going to be difficult when trucks come in for service; extra downtime may be an issue as technicians may need extra time to double check what oil is required,” he continues. “And are you going to add cost to pipe in an extra bulk oil line or take a time penalty for a tech to walk across the bay to get CJ-4 in bottle or drum storage?”

Pond points out that the extra space could be put to better use.: “Why stock two oils when can use space to stock vital engine parts?

“Look at the complexity of investment required for two oils,” says Reginald Dias, director, ConocoPhillips Lubricants, 76 Lubricants and Conoco brands. “You are talking two storage tanks instead of one, two separate inventory costs, and your potential for mix-up is far greater. So the overall savings of stocking two oils versus switching to a more expensive CJ-4 may be washed out‥”

Some think that fleets should sit down with their lubricant provider to review the particulars of their operating environment before embarking on an '07 oil strategy.


“Customers shouldn't make this decision off the cuff,” explains Dargento. “You need to look at the fleet's profile and its oil consumption pattern to make that switch decision. If you go with two oils, maintenance needs to keep a close eye on every oil change to prevent misapplication. Fleets shouldn't have any problems handling two oils if they approach it the right way.”

Right now, Dargento says Chevron doesn't see a big rush among fleets to convert to CJ-4 wholesale, and like every lubricant maker, it doesn't intend to force customers to switch to just one oil. But he does feel that a “tipping point” will be reached sometime next year when switching completely to CJ-4 will make the most sense. “When the '07 portion of the fleet becomes dominant, that's when it's time to convert.

“Some fleets may flip to CJ-4 when the first '07 truck enters their fleet; others may carry two oils for a time,” adds Shell's Arcy.

ExxonMobil's Pond says the feedback his company is getting from big fleets is that they'll switch to CJ-4 across the board once they start getting '07 trucks. “However, smaller fleets probably won't get with '07 engines until the middle of next year. For them, switching to CJ-4 depends on the arrival date of '07 equipment,” he says. “If there's a tipping point, it's likely when 25% of their fleet is made up of '07 engines. The economics of keeping two oils beyond that get dicey.”

Fleets are also coming up with novel ways to manage the oil changeover. “Our plan is to have the oil four our '07 equipment exclusively changed on the road [at truck stops and other third-party maintenance outlets] so we can stay with just one oil in our shops,” says Jeff Bryant, vp-maintenance for truckload carrier Celadon Group.

“We need to stay with our current [CI-4] oil to service our fleet of 2,800 trucks because we don't want to inflate our maintenance cost” by using more expensive CJ-4, he says. “Our current engine oil already gives us 30,000-mile drain and handles the higher heat rejection loads [from current emission-compliant engines] just fine. Trying to justify 10% higher cost for new oil without a longer drain or another direct benefit is very hard.”

However, that's going to change once Celadon reaches a tipping point, Bryant says. “As soon as we have enough '07 trucks — roughly 200 out of 2,800 — we'll go to CJ-4 across the board. We also perform regular oil analysis, so we'll see if we can extend the drain [interval] long for CJ-4 to justify the higher cost. We don't want to stock two oils; that requires twice the equipment and [means] a 50% chance we'll make a mistake.”

Bryant says the key to his decision-making is making sure his fleet's engines have the right oil, at the right time, at the best cost possible. “We're trying to be proactive in addressing this,” he adds.

Making the switch

So you've decided to switch your fleet over to CJ-4. If you use bulk storage tanks in your shop, you're now facing the challenge of making that change in the most economical manner possible. Dan Arcy, technical marketing manager for Shell Lubricants, has a few tips.

  • If you have a tank that's no more six months old, use up as much of the CI-4 remaining in your bulk tank as possible; try to get it down to 2% or less.

  • If your tank is no more than six months old, you don't need to clean it before adding the CJ-4.

  • If the tank is older than six months, it's best to drain and clean it completely before putting in the CJ-4. This will get rid of any debris that has accumulated, as well as ensure that you have a moisture-free tank.

  • If you live in a state that requires regular tank inspections, have it done before you switch to CJ-4.

  • If you can't clean the tank, draw down the CI-4 level to 2% or less before adding the CJ-4.

  • Arcy points out that pre-'07 engines can handle a mix of CI-4 and CJ-4 with no problem. If you need to top off with a quart on the road, you can add CJ-4 to an engine reservoir full of CI-4.

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