TORONTO -- It may not believe in SCR technology as an emissions solution for North America, but Navistar is apparently going with the aftertreatment strategy on its engines in Brazil.

Navistar International, of course, is the only major truck OEM to decline SCR in Canada and the U.S., continuing instead with "advanced" EGR. Though, according to the products page on its website, Navistar's MWM International Motores subsidiary is employing SCR in its NGD 9.3E medium-duty engine for the South American market. 

Spokesman Roy Wiley confirmed to todaystrucking.com that MWM would build SCR engines in Brazil. He said the engines are at the request of Volkswagen Truck and Bus, Navistar's largest South American customer, in meeting the Euro IV emissions standards Brazil has adopted.

"Regulations, conditions, and environmental issues are different in Brazil and other parts of the world," he said. "We're a big supplier to Volkswagen and so we work with them."

Wiley, however, couldn't say off-hand whether MWM is working with an independent partner to produce the SCR engines.

In the seemingly endless war of words between the EGR and SCR camps, Navistar has been vocally critical of SCR as a North American emissions solution. But Wiley says such a characterization is "unfair," adding that the company has only "discussed" the use of "urea" in 2010 SCR engines. "There's a big difference."

Wiley couldn't confirm whether urea -- or more accurately, the urea-based NOx-busting chemical Diesel Exhaust Fluid (AdBlue in Europe) required in most SCR engines -- will be used in the Brazilian NGD engines as well.

In the past, Navistar officials have wrongly called DEF a "toxic" substance.

Whether the company has been overly critical of its competitors' platform technology or not, it certainly hasn't pulled any punches on the EPA's decision to allow drivers and maintenance staff to self-monitor DEF levels in the SCR system.

Recently, Jack Allen reiterated court documents filed by Navistar that accuse the EPA of "creating a loophole for SCR manufacturers."

The company stated that allowing trucks to continue rolling on the highway, albeit ramped down, in rare instances that the DEF tank runs dry, gives SCR makers a "licence to pollute."

Earlier this year, sales exec Jim Hebe said "(SCR) could be the biggest false-start in trucking history." He predicted that emerging technologies will come online without the need to use a urea-based aftertreatment catalyst like DEF.

International Truck & Engine President Dee Kapur basically said the same thing at a Heavy-Duty Manufacturers Association conference in Las Vegas last year.

"There may be some applications for SCR, but if so, we think it's a stop-gap solution, and it will be marooned in the future," he said pointedly.