Oil filtration has not been significantly affected by changes in engine technology to meet emissions standards, but there are some other trends.

Lube filters have three performance criteria, explains Keith Lilly, global product manager for Cummins Filtration: efficiency, capacity for contamination and low oil flow restriction.

"High quality and high performance filters are a balance of these criteria," he says. "However, the amount of harmful contaminant (capacity), the size of the contaminants (efficiency), and the life that an oil filter is expected to have (capacity and low restriction), are impacted by changes with each emission standard, and engine manufacturer. Fleets' and owner-operators' desires for longer service intervals also impact these factors."

John Gaither, vice president of engineering and quality at Luber-Finer, says the new additives that replaced the traditional ash-producing ones in the CJ-4 oil category "certainly caused us to step back and take a hard look at the filters themselves.

"Probably the biggest challenge is the newer engines are running hotter and have the tendency to generate more soot," Gaither says. "Consequently what the oil filter sees may be a higher contaminant load than what it saw in the past."

Kenny Cameron, product manager for Fram Commercial Vehicle/Heavy Duty, says he sees the next generation of oil filtration focusing on soot. "The soot in the oil is present because it's not going into the air," thanks to emissions regulations, he says.

At Puradyn, President Kevin Kroger says that due to some of the byproducts of combustion and aftertreatment, the oil is starting to get a little "dirtier."

"There's a lot of activity among the oil companies coming out with oils that can help extend oil drain intervals with the new emissions standards," Kroger says. "The problem is they're still not addressing the filtration issue. At the end of the day you still have to maintain the cleanliness of the oil, and that's becoming more and more critical with today's engines."

It becomes even more critical when looking at extended drain intervals. "Lube filtration has primarily been challenged through OEM and end user desires to extend drain intervals beyond the traditional 25,000-30,000 miles," says Keith Bechtum, liquid filtration product specialist for Donaldson. "We have seen many OEMs asking for 50,000-mile-plus filter life technology."

Cummins' Lilly recommends keeping service intervals in mind when selecting oil filters. "Oil filtration products that are suited for longer exposure to hot oils and that can manage the extra sludge loading while flowing freely will be the best choice for extended service interval applications."

ADDITIZATION

A growing number of companies are offering oil filters that promise to put additives back into the oil during the filtration process and help extend oil drain intervals.

Donaldson's Endurance Plus filter replenishes oil additives to help standard mineral grade oil to reach longer drain intervals.

Puradyn has been treating oil with additives for some time with its bypass filtration system. "It's critical to extending oil drain intervals, to keep the viscosity and chemical balance in check," explains Kroger. "And over the years we've found what's extremely critical is the rate at which you release these additives back into the oils. Too fast causes imbalance of the chemicals; too slow and the additives deplete over time."

When the CJ-4 category came out, with its very different chemistry, Kroger says, a lot of time, research and energy went into changing their formulation to adapt. "It took us about two years of working with an oil company, an engine manufacturer and a couple of additive companies to come up with our additive package formulation, making sure it was compatible with both the new oils as well as the previous oils," he says.

Fram is the latest addition, launching its TRT (Time Release Technology) line of filters later this year. "It's an additization filter, which impedes the degradation of the oil's TBN," explains Cameron. The new filter releases the additive linearly - with each pass through the filter, the filter releases a precise of additive into the oil, he explains. Fram is launching it through an OE truck manufacturer under their label before rolling out the Fram brand for other engine makes.

"The additive company we're using is very well known in the industry, and it's formulated for the engine application," he says. "I've been working on this project for two years, and we've done extensive road testing and dyno testing."

Not so fast...

Many oil and engine makers, however, are skeptical.

"Potentially, it sounds good," says Bob Theisen, manager of technical services for CHS, which makes Cenex brand lubricants. "But you've got to think about the chemical restrictions that are now on CJ-4 oils. Then you have additive compatibility to think about, and when those products get into the marketplace there's a vast variety of chemistry they have to live with. I suspect it has potential, but from my perspective, it's still in its infancy."

One engine maker investigated oil additization technology in depth and concluded there was very little benefit. Most oil drains are either soot-limited or TBN-limited, they said. The additive release technology did nothing to remove soot from the oil and only marginally showed any benefit to TBN. In their tests, only about half of the additive was actually released from the filter in 50,000 miles, and they also found it contributed more ash to the engine oil.

"We don't agree with any aftermarket additive treatment to a multi-million-dollar formulation," says Mark Betner, heavy duty lubricant manager for Citgo. "We don't know what they're adding back in the oil, we don't know what impact that has on the expensive licensing we had to go through. You don't go to the doctor, get a prescription, then go the shelf of the pharmacy and put something else in there. How does that filter manufacturer know what to put back in that oil, how much, and how do they know what condition the oil is in to begin with?"

Reginald Dias, director of commercial products for ConocoPhillips Lubricants, explains further: "Modern engine oils are formulated with a combination of several additive components to meet the total lubrication requirements of an engine. Post additization of engine oil with aftermarket additives to improve oil performance or extend its life is not recommended. Some OEMs explicitly prohibit use of such additive supplements in the oil used in their equipment.

"The engine oil is formulated with a carefully balanced composition of dispersants, detergents, oxidation inhibitors, anti-wear compounds, corrosion preventative chemicals, rust inhibitors, etc." Dias explains. "Supplemental additives, whether poured into the crankcase or slowly dispensed through a time-controlled release process, can upset that balance. For example, use of a post treatment additive may show improved cleanliness but may cause catastrophic wear or corrosion because the wear and corrosion preventing additives were rendered ineffective. In extreme cases this could lead to catastrophic engine failure."

In addition, says Cummins' Lilly, many supplemental oil additives actually increase the ash content, which shortens the DPF's service life. He says engine OEMs do not generally endorse the use of engine oil additives.

Walt Silveira, North American technical manager for Shell Lubricants, says the engine OEM should be your main source of guidance in this area, and points out that the oils are designed to protect a truck buyer's investment in his equipment without any extra additives. That said, however, "If we can find a business solution that will help our customers improve their maintenance practices, we try to help them," he says. "We have customers that are testing different types of filtration systems. We try to help them understand if there is a benefit to that or not."

The bottom line? Work closely with your engine manufacturer and your lubricant supplier if you want to evaluate the potential of additization products for your operations.

GOODBYE SPIN-ON?

Filter makers say they're seeing increasing interest in cartridge filters and modular designs, rather than the spin-ons we've become used to. That's because the cartridge filters, without that metal housing to be disposed of, can easily be compacted or put into an incinerator.

"Everything's going to element-style filters where they go into a permanent housing on the vehicles, instead of spin-on filters," says Jason Snider, a mechanical engineer for Luber-Finer's heavy duty liquids group. "Why? Environmental friendliness and a look at trying to reduce the costs of operating."

John Gaither, Luber-Finer vice president of engineering and quality, notes that most of these element- or cartridge-style filter designs originated in Europe. "As U.S. manufacturers become affiliated with European companies, that technology tends to drift over."

However, it is a different technique to change the filter, he says. Technicians will now be dealing with removing and replacing housing caps and an O-ring seal they haven't had to deal with in the past.

"You've got two generations of technicians that have not done a lot of work with cartridge filters," says Paul Bandoly, manager of technical services and customer training for Wix Filters. "So learning how to properly service the modules and the cartridge-style filters is very important in the shop."

BIODIESEL & ENGINE LUBRICATION

As skyrocketing oil prices increase the interest in biofuels, oil companies and filter manufacturers are taking a closer look at how higher blends of biodiesel might affect the engine lubrication system.

Most engine builders allow use of 5 percent (B5) to 10 percent (B10) biodiesel in their engines without any reservations. Most modern CJ-4 lubricants are believed to be compatible with use of biodiesel fuel at these levels.

But as interest in higher blends of biodiesel increases (Minnesota recently passed a law that will phase in 20-percent blends, or B20), it's possible that oil formulations may be tweaked to deal with some of these concerns.

"I think a lot of folks forget when they start using biodiesel that some of it will end up in the crankcase," says Paul Bandoly, manager of technical services and customer training for Wix Filters.

"The contaminants that accumulate in the oil are combustion byproducts," explains John Gaither, Luber-Finer vice president of engineering and quality, "and those byproducts differ significantly when biodiesel fuels are burned."

Keith Lilly, global product manager for Cummins Filtration, notes that there have been some instances of biodiesel fuels creating situations that have altered the combustion process and have resulted in premature plugging of oil filters due to sludge-like resins. "Following the latest biodiesel fuel standards has helped minimize many of these early issues."

However, fuel dilution - when unburned fuel gets past the piston rings and mixes with the oil - can pose a problem, Lilly says. "This is generally not a problem, as engine temperature tends to evaporate diesel fuel. [But] biodiesel does not evaporate as easily."

This kind of fuel dilution can decrease an engine oil's viscosity and lubricity, and can alter the performance of anti-wear additives. "It's critical to monitor engine oils for excessive fuel dilution when using biodiesel fuels, because the resulting wear occurs more rapidly," Lilly says.

Kevin Kroger, president of Puradyn, which markets bypass oil filtration systems, says that especially when you get beyond the B20 level, "what we're seeing is an increased amount of water buildup inside of the engine, and we're also starting to see some fuel dilution [of the oil] taking place."

Mark Betner, heavy duty lubricant manager for Citgo, says the impact of biodiesel on oil conditions could prompt engine manufacturers to put a test in place to see how a company's CJ-4 oil behaves in engines operating on biodiesel. "Biodiesel does tend to maybe increase the oxidation of the oil and therefore potentially could cause a little premature oil breakdown in some cases," he says. "There's no tangible, hard data yet on that, but there's some speculation that there may be something we need to look at."

To get that data, there is testing in the industry looking at biodiesel, particularly B20, says West Alexander, product specialist for Chevron. "They're taking a look at the effect it has on oils, particularly oxidation, nitration, and what effect fuel dilution will have on oil in engines using biodiesel. I think they're seeing some significant increases in oxidation with B20 biodiesel, but not a significant viscosity effect."

Engine OEMs currently are comfortable with CJ-4 products up to the biodiesel blend levels they've approved, says Walt Silveira, North American technical manager for Shell Lubricants. "Right now, they're not sure of the extent of how much further you can go past B20. In a lot of states there are some tax benefits of using biodiesel at higher levels. We're trying to make sure we're testing our lubricants in those type of environments [to see if] there's any need to make any adjustments to the formulation."