Oil category tailored for '98 diesels won't be in place when those engines are, but will be worth the wait.

Waitin' round the bend, our new lubricant friend ... Like those drifters off to see Moon River, trucking eagerly awaits the appearance of "PC-7" motor oil.

However, seeking out a fictional stream is one thing. Testing the waters for a new heavy-duty oil category is something else.

Figuring out how to make lubricants meet advanced performance demands is always key to the oil-classification process. But that's just the overview. Each time a category is proposed, engine builders can establish testing protocols to determine how a new oil spec would affect specific concerns. Each of these tests must be developed, calibrated, and passed before a new category can be marketed.

Creating an oil category involves highly technical work that must be completed by industry committees well before individual suppliers can formulate products to the new spec.

To be perfectly clear, there is no PC-7 oil yet. That moniker refers only to the latest "proposed category" for API (American Petroleum Institute) oil classification. This proposal will enable suppliers to formulate lubricants for use in diesels certified to 1998 federal-emissions regs.

Oils meeting the PC-7 spec will ultimately be stamped with a new API designation, most likely "CH-4."

Piloting PC-7 to maturity is arduous work because of its demanding charter. Working with engine and additive counterparts, lubricant engineers are crafting an oil spec to counter anticipated performance demands on diesel engines.

Therein lies the rub. As of next January, new heavy-duty diesels will have to meet federal 1998 emissions regulations. But at this writing, oil officially certified to the final PC-7 spec won't be on the market for at least another nine to twelve months after that.

The hard truth is that every process has to start somewhere. "It's hard to develop an oil for an engine that doesn't exist," remarks Bob Juett, Shell's project leader-heavy-duty diesel lubricants.

"But as engine manufacturers work to meet emissions specs," he continues, "lubricant engineers use test data and actual hardware as it becomes available to develop new oil.

"Engine makers provide ballpark parameters for developing a next-generation oil," Juett explains. "Lab results on engines in test cells help further define performance targets for the new oil."

Since oil formulation is not a factor in emissions certification, engine makers don't need a PC-7 or similar oil to be ready for '98. "Once those engines are in the field," Juett states, "manufacturers and fleets will want to service them with the most suitable oil."

The first industry organization to sign off on PC-7 will be the ASTM (American Society for Testing and Materials) Heavy-Duty Engine Oil Classification Panel.

Chairman of the aforementioned ASTM panel is Jim McGeehan, Chevron's team leader-engine oils. Though specific goals and challenges may change, he states that developing new oil categories is "always about continually improving oil quality."

According to McGeehan, the classification process typically upgrades oil quality every four years, "particularly concerning wear protection." However, he says PC-7 is being "driven by design changes engine manufacturers are making to meet the '98 emissions rules."

McGeehan lists the following factors related to '98 emissions regs as critical to the development of the PC-7 spec:

1. Nitrous-oxide (NOx) levels must drop from 5 to 4 grams. "With that reduction, engine makers will have to retard timing -- and that increases soot in the oil."

2. Wear protection. "The new Cummins M11 test includes criteria for cross-head abrasive wear and the Mack T9 focuses on ring and liner wear."

3. Caterpillar 1P is the first test to focus on two-piece pistons. "This means the oil category must also address deposit control."

4. Soot limits will go from 3.8% out to 4%. "The '98 engines will need oil capable of greater soot dispersancy."

In the end, says McGeehan, the new category will "increase oil performance for both engine-wear protection and extended drain intervals."

The development process is on track, according to McGeehan. His timetable indicates certified oil will reach users by September 1998.

"Preliminary work is under way to tell us if each test is suitable for the category. Our testing matrix will also indicate which of three base-stock oils is most severe -- so other base stocks won't have to be tested later," McGeehan reports.

"We'll have the limits set for classification by this September," he continues. "Once that's done, API imposes a one-year delay so that all oil companies can have time to qualify their products for the new category."

But the biggest drag on pushing PC-7 through has been the cost of preliminary testing deemed necessary to make the effort as worthwhile as possible. "This is the first time ASTM has run a category that required multiple testing," says McGeehan. "And it can cost $45,000 to conduct each test needed."

The cost to suppliers of the ASTM testing, including the new Cat 1P, Cummins M11, and Mack T9 engine tests, is tagged at $5 million. Accounting for part of that expense was the decision to produce the first matrix that features base-stock severity.

"In the past, base-stock testing wasn't done until after the category itself was completed," points out Dan Larkin, Detroit Diesel Corp. senior chemist-fuels & lubricants, who chairs the lubrication committee of the Engine Manufacturers Assn. (EMA).

"In the past," Larkin says, "determining the base-oil interchange for testing was left for API and the various oil companies. That made for a costly, helter-skelter process because of so much redundant work."

According to Larkin, adding the base-oil interchange up front has doubled the price of the ASTM matrix but it will save millions of dollars over the long run. "The other advantage is that all this data comes in for everyone to look over at the same time. So, this category can be under way a few months after matrix testing is completed."

Until the new category is certified by API, lubrication engineers will likely recommend -- at minimum -- that '98 engines be run with a "premium" motor oil. However, some oil companies may provide oil that unofficially meets the PC-7 spec before then.

"We won't claim our oil meets PC-7 until we can," remarks Shell's Juett. "But our premium multigrade will use a new soot-control formula to help meet the service requirements of '98 engines."

Also recommending that fleets treat '98 power to a premium oil until the category becomes effective is Chevron's McGeehan. "Premium products offer more additives and higher quality," says McGeehan, "and major oil companies have already done a lot of testing. We've put our oil through the new tests and it has performed well," he relates.

Fleets may also be advised by oil and engine suppliers to reign in extended drain intervals until the new API "donut" is rolled out.

For example, Detroit Diesel's Larkin says the engine maker is considering recommending that fleets not extend drain intervals on its '98 engines before the new oil is officially released.

"I believe we'll also recommend that fleets put those engines on oil analysis to ensure the oil they've selected is standing up even to shorter drain intervals," Larkin reports. "Our normal highway drain recommendation using CG-4 oil is 15,000 miles," he adds. "Given our current thinking, we may pull that back to 10,000 or 12,000 miles on '98 engines.

"Manufacturers may also opt to issue their own specs for '98, to ensure an interim or replacement oil satisfies their concerns," Larkin remarks.

Chevron's McGeehan says that once PC-7 is done and wrapped it will enable oil companies "to offer the best-quality crankcase oil available in the world for heavy-duty trucks."

Still, it won't be long until ASTM embarks on another proposed category. "Under the 2004 emissions regs," McGeehan advises, "NOx will drop to two grams. Meeting that may lead to engineering heavy-duty diesels with exhaust-gas recirculating (EGR) technology. That would further increase the need for good wear protection."

The hope is for smoother sailing the next time out. "Thanks to what's been done on PC-7," McGeehan points out, "the industry already has a better approach in place for planning and funding the next diesel-oil category."

Oil categories are developed through the cooperation of five industry groups: the Society of Automotive Engineers (SAE), the Engine Manufacturers Assn. (EMA), the American Society for Testing Materials (ASTM), the Chemical Manufacturers Assn. (CMA), and the American Petroleum Institute (API).

The categorization process begins with TC-2, an SAE technical committee. TC-2 receives requirements for an oil from EMA. Ensuring that oils meet these criteria is the most important role of the classification system. Fleet operators have their own concerns, such as longer drain intervals and less waste-oil disposal, which are also addressed by the SAE committee.

TC-2 sends its recommendations to the Heavy-Duty Oil Classification Panel (HDOCP) of ASTM. This panel of representatives from oil companies, additive suppliers, and engine makers essentially develops the new classification. HDOCP defines the tests and limits necessary for an oil to fit the category.

These tests are examined for accuracy and reliability before being voted in as part of the classification. This alone is an arduous and exacting process, given the variability of the tests and the number of competing interests involved. The category is then voted on by four ASTM committees before it is passed.

Once the preliminary tests have been established by ASTM, oil companies can run their own formulations for a new category. This testing is done under the auspices of CMA. If passed, an oil can display the API seal of approval, a.k.a. "the donut," which ensures buyers of its recommended service category.