Despite the Environmental Protection Agency's reaffirmation that it won't adjust the 2010 emissions standards timetable — and the widespread support of that decision among truck and engine OEMs — it'll be far from a smooth ride.

For starters, Warrenville, IL-based Navistar isn't letting up in its effort to get what it calls an “economic extension” from the EPA, which allows engine makers to build products that meet only the 2007 engine standards beyond the Jan. 1, 2010, deadline. In fact, the company is pushing ahead with plans to introduce a new 15-liter engine under its MaxxForce label — rumored to be a revamped Caterpillar C-15, a by-product of the partnership Navistar forged with Caterpillar last August.

“All I can tell you is that we're going to have a 15-liter MaxxForce engine,” Navistar spokesman Roy Wiley told Fleet Owner. “Anything else is pure speculation.”

A 15-liter product would give Navistar a significant competitive edge in the Class 8 market, as it currently only builds 11- and 13-liter models under the MaxxForce brand. Navistar's current main supplier of heavier duty engines — Columbus, IN-based Cummins — is adopting SCR technology to meet 2010 regulations; a technology Navistar is forgoing in favor of an advanced EGR package. So instead of facing a gap in its engine offerings due to the Cummins technology decision, Navistar is now poised to have its own all-EGR 15-liter product available for customers — albeit one for which it will still need to use credits to get certified.

In the meantime, Cummins is facing its own challenges as the EPA contends that the copper zeolite used as the catalytic material in its SCR emissions control system may produce carcinogenic dioxins — meaning the agency might not certify Cummins' product line for 2010.

In a Dec. 11 letter to Cummins, EPA said that it would do its own testing on engines with an SCR system that uses copper zeolite, and it could reject the engines even if the tests are inconclusive. However, Tina Vujovich, vp of marketing and environmental policy for Cummins, told Fleet Owner that the EPA's concerns are overblown. “Based on what we've seen so far, we don't have any concern about dioxins,” Vujovich said. “What EPA is doing [with SCR] is no different from what they did when EGR came about. It's a long process.”

Steve Charlton, vp of heavy-duty engineering for Cummins, stressed to Fleet Owner that the molecular structure of copper zeolite by its very nature vastly reduces the risks that dioxin might form in the exhaust stream.

“For dioxin to form in the exhaust stream, you need the presence of a number of materials: a large hydrocarbon molecule, chlorine and access to the catalyst,” he told Fleet Owner. “So, first of all, there is very little chlorine produced in diesel combustion. More important, however, is the molecular nature of our copper zeolite catalyst.”

He noted that the molecular structure of the zeolite surrounds the copper in a ‘cage’ made up of very small tunnels that allow the passage of ammonia from the urea and oxides of nitrogen (NOx) but not of large hydrocarbons. “Those hydrocarbon molecules are simply too big to fit into those tunnels, meaning the chances they can come into contact with the copper to produce a reaction are extremely small,” Charlton said.

Because of copper zeolite's benefits, Vujovich feels the company should have no problem passing EPA's inspections. “EPA is not in the business of shutting down manufacturers,” she said. “If they thought [copper zeolite] was a showstopper, they would have already told us. We feel very confident in the work we've done, and it's in their best interest and our best interest to get this approved.”

“Cummins 2010 engines will deliver what customers need in these challenging economic times,'' adds Jim Kelly, president of Cummins truck engine group.