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NEW OILS FOR NEW ENGINES

Posted: August 1, 2014 by Jim Park

At least we won’t need new tires come January 1, 2007. Little else, it seems, will emerge unchanged come the New Year. Frames, mufflers, electronics, fuel, engines of course, and more, are being tweaked and tuned to meet the 2007 low-emission EPA mandate. Count in engine oils too.

Because of the potential for premature clogging of the exhaust filters, lube engineers have had to reduce the sulfur and ash contents of their product, while at the same time improving the overall performance of the oil. A new oil category called CJ-4 is the answer.

“In previous categories, the primary objective was to focus on oil’s contribution to engine durability or maximum engine life,” says Mike Dargento, Chevron commercial sector and brand manager for on-highway. For 2007, there are two new elements in the mix: diesel particulate filters (as explained on page 22) and ultra-low-sulfur diesel fuel. “In 2007, in addition to looking at engine durability, we looked at DPF life, as well as the utilization of ULSD, and those two elements became design targets for the oil category.”
When the new oil classifications for the 2007 engines were first discussed “there was massive panic in the industry,” recalls Steven Goodier, technology manager for BP Lubricants. “People thought there would have to be a compromise” between performance and backward compatibility.

Because of these aftertreatment devices, for the first time the oil category contains numerical limits on the amounts of certain chemicals in the oil: sulfated ash, phosphorus, and sulfur. The oil companies use the acronym SAPS, and call these low-SAPS oils. These compounds must be kept to a minimum because they can foul the aftertreatment devices.

The problem is, those very same compounds are what oil makers have used for decades to do things such as neutralizing acids and preventing wear. This meant going to entirely new additives.

So the new oils have been designed to withstand higher temperatures, with better oxidation resistance and better deposit prevention, plus better dispersancy to handle higher levels of soot, explains Alex Bolkhovsky, commercial vehicle lubricants technical advisor for ExxonMobil Lubricants. “And of course, higher heat requires an overall rebalance of the oil to make sure they really perform better in all areas, including wear and detergency. The minute you have higher levels of heat, things tend to degrade faster.”
All this had to be done without using the conventional SAPS additives the industry has used for decades.

For instance, sulfated ash has traditionally been used to neutralize acids. This ability is measured by a TBN number. “Under traditional chemistry, lower ash means lower TBN,” says Dan Arcy, technical marketing manager for Shell Lubricants. At the same time, higher EGR means more acids in the oil. Fortunately, the ultra low sulfur diesel will help counteract this, with less sulfur that can be transformed into sulfuric acid during the combustion process.

According to Jim Putz, category manager, commercial transportation lubricants, at Petro-Canada, the chemical formulation of these oils has changed altogether.
“These oils are formulated to enable the use of increased EGR rates and new exhaust aftertreatment devices in 2007 on-road diesel trucks to help meet the 2007 EPA exhaust emission standards,” he says.

To be compatible with exhaust aftertreatment technology, CJ-4 oil must meet chemical restrictions of less than:
* 1.0 percent ash;
* 0.4 percent sulphur;
* 0.12 percent phosphorus.
These limits were not in place for the previous API CI-4 Plus category.

“Higher quality base oils (Group II and higher) will be required in order to pass 10 engine sequence tests (new and old tests) and six bench tests set at higher pass limits than the previous category API CI-4 Plus,” Putz points out. “The higher sulfur limit of 0.4% also minimizes the possibility of using higher-sulfur Group I base stocks.”

Bolkhovsky compares the challenge to food: “It’s like saying, ‘This pizza tastes great, but I want a low-fat pizza that tastes even better.’ That’s what we had to do – design an oil with fewer conventional components that worked even better.”
That meant going to entirely different additives. “We’ve had to start looking at more novel and new anti-wear chemistries, detergents, dispersants, which before now were either prototypes or were only used in niche applications,” says BP’s Goodier.

CJ-4 oils have been designed to deal with higher engine heat.

Backward Compatibility
That’s a term you’ll be hearing more of in the future. Essentially it addresses the need for product designed to work in the 2007 engines while still meeting the needs of pre-2007 engines.

Backward compatibility “is something that the industry had an eye on right from the beginning,” Bolkhovsky says. “Because of the performance requirements these oils will have, we feel pretty confident we will have backward compatibility.”

Although the new oils should be backward compatible with pre-2007 engines, at least in on-highway applications, it looks like CI-4 oils will continue to be available alongside the new CJ-4 formulation. This is a departure from previous category changes, where the old formulation pretty much went away after a transition period.

“Historically in North America, when new specifications come out on the market, they replace the old one,” Goodier says. “With the introduction of CJ-4, you’ll have CI-4 oil still out there, to allow people operating older vehicles to continue to have access to these products.”

There are several reasons you might want to continue buying CI-4 oils for your pre-2007 equipment. One, the new oils may be more expensive. Two, they might not work as well in some severe-duty applications. Three, they might not allow oil drain intervals to be extended as much as some fleets are doing today.

“You’ve got 95 percent of the on-highway truck population made up of earlier models,” says Dargento, “and those older vintages don’t necessarily require the CJ-4 formulation. So we’re seeing the market somewhat fragmented for the first time, seeing demand for different formulations in the same sector for the first time.”

We’ve recently seen Petro-Canada and Chevron announce the readiness of their engine lube products, and the other majors will be doing the same over the next few months. The target date is the fall of ’06, to be ready for the roll out of the ’07 engines. Will they cost more? That’s likely, given the research and development investment necessary to get to API CJ-4. But the market will be a factor too. Demand for CJ-4 won’t be high at first, given the relative scarcity of ’07 engines in the very near future.

With CI-4 still on the shelves, many users may opt to use the existing product as long as they can get it, and of course point-of-purchase price will be a factor.

But the oldest adage in the book still applies: you get what you pay for. By all accounts, CJ-4 will be a higher-quality oil.

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