TORONTO, Ont. – Despite the array of engineering challenges, tighter emission standards being introduced in 2007 may seem more like a speed bump than a technological hurdle.

Manufacturers are already testing prototypes of some of the cleanest engine designs in history, production models are on schedule to be introduced next year, and their Ultra Low Sulfur Diesel (ULSD) fuel will soon be available across North America.

That said, there are still several questions about the new oils being formulated to protect this equipment, and the answers from suppliers tend to be somewhat vague.

How much will the new oil cost? Don’t know. Will it be “backwards compatible” so it can be used in existing engines? Should be. Do oil suppliers know about the tests to be required by individual engine manufacturers? Not yet. When will it hit the shelves? Not completely sure.

If there is one certainty, however, it’s that the new oils are a key element in the changeover of engine designs.

“The reason for the development of the category (of oil) is to protect the emission devices,” says BP Lubricants’ Mike Lynskey, referring to the new diesel particulate filters that are being added to capture tiny Particulate Matter.

Today’s oils include an ash that’s used to counteract the sulfuric acid created from the sulfur found in today’s diesel fuel. (Think of it in terms of a microscopic Rolaids.) But since that ash can build up in particulate filters, the industry is being supplied with Ultra Low Sulfur Diesel, allowing oil suppliers to lower today’s ash levels of 1.3 to 1.5 per cent to less than one per cent by volume.

That will be a key factor to ensure that the new filters can last at least 400,000 km before needing to be changed, says Imperial Oil’s Clinton Smith.

As important as the changes are for future equipment, however, the oil suppliers need to be mindful of the needs of engines that are already on the road.

“Backward compatibility is one of the design targets for PC-10 (the temporary designation for the new oils),” says West Alexander, Chevron Global Lubricants’ senior staff engineer, engine oil technology. But drain intervals may need to be shortened if the new oils are used in today’s engines, he adds, referring to the different “chemical box” that places limits on the way formulas will be created. “This means PC-10 oils may not be drop in-replacements for current CI-4 Plus oils.”

“We do know that PC-10 oils will work in older equipment, will work with higher-sulfur fuels. The question is the drain interval,” agrees Alex Bolkhovsky, commercial vehicle lubricants technical advisor with ExxonMobil. “The basics of what the oils have to do are not going to change much. It’s the extra acid brought into the equation.”

Still, Smith says there’s no reason to panic. Changes in potential oil drain intervals, if they come at all, are expected to be relatively minor when compared to past experience.

“The (Exhaust Gas Recirculation) engines took a beating in drain intervals relative to where we were with CH-4 oils in 1998 engines,” he says. “To take a further reduction with the PC-10 would be a hard pill for the industry to swallow…they’re desperately trying to extend the intervals with their (existing) engines.”

Of course, there is a cost associated with every change in chemistry. New limits on levels of phosphorous – a key element in a common anti-wear additive known as ZDDP – will require an alternative that will undoubtedly be more expensive, Smith says as an example.

It simply seems that nobody is exactly sure how much the final price point will be.

“We cannot quantify the price increase because test limits have not been set,” Alexander says.

Indeed, the American Petroleum Institute’s initial requirements simply offer a baseline from which everyone will work. Individual engine manufacturers are expected to release test requirements of their own early in 2006, largely building on standards that they have already set. Mack, for example, designed viscosity tests in the past, reflecting the focus on soot that can be generated by refuse trucks that idle for extended periods of time. Cummins, meanwhile, set accepted tests for valve train wear, while Caterpillar looked at piston deposits.

In the end, fleets are expected to have a choice between two categories of oil when the new engines are introduced, albeit for a limited period of time.

Options will include sticking with old oils at the expense of the diesel particulate filters to be found on new equipment, or outsourcing work on the next generation of engines to maintenance shops that have new oils on hand. Still another option will be to stock two types of oil to meet the needs of the existing and new engine designs, although that presents a fair share of challenges.

“Most fleets want to use one oil because it minimizes complexity,” Alexander says. The use of two oils means adding yet another category to a shop’s inventory efforts, and tracking whether maintenance teams are putting the right oils into the right sumps.

“People make mistakes,” says Stephen Miller, Shell Canada’s product manager, heavy-duty and passenger car engine oil. “The ability of a fleet to keep old oil out of the new engine would be pretty low. There really is little prevention other than good maintenance practices in the shop.

“Anytime you make things complicated, it can be expensive.”

“Using today’s oils isn’t necessarily going to harm the engines,” Bolkhovsky adds. But it would damage the exhaust aftertreatment devices, and such decisions would keep fleets from enjoying other improvements associated with the new oils.

While ash levels will be lower, the new oils are also expected to better handle engine deposits, disperse soot, and protect a variety of components from premature wear.

Perhaps the questions about price are even premature when you consider that the industry doesn’t know what the new formulas will be called.

The PC-10 designation refers to a “Proposed Category,” and the decision to name the successor can’t be made out of hand. On the automotive side of the oil business, plans to name standards with an SK had to be skipped because it matched the name of a refinery in Korea, and SI couldn’t be used because it is the designation for an international system of measurement.

Could CJ-4 be dumped because of a vehicle once known as the Jeep CJ? Who knows? And, really, who cares?

In general, most suppliers of engine oils expect to have their products in the market by late 2006, whatever they’re named.

It’s the price that will ultimately determine how smooth the transition will be.