LISLE, Ill. — Navistar International announced recently that it will offer the Cummins ISB mid-range engine in its DuraStar medium-duty trucks.

The ISB will represent the first mid-range engines to use selective catalytic reduction (SCR) within the Navistar product line. The company will continue offering its own proprietary engines with exhaust gas recirculation (EGR), and has “an adequate number of credits” to do so, well into next year, said Bill Kozek, president, North America Truck and Parts with Navistar. This move buys the company more time to adapt SCR to its mid-range MaxxForce engines.

Adding the ISB engine is “an important part of our SCR product strategy,” Kozek said during a media briefing this afternoon. Initially, the ISB 6.7L engine will be offered only in the International DuraStar, as well as the company’s school buses. Orders can be placed for trucks with the ISB immediately, with production slated to begin later this month and ramp up to full volumes by December.

“We’re making this move for three key reasons,” Kozek said. “First, it allows us to get into the market today with medium-duty SCR vehicles. Second, like the ISX, the ISB is a proven, accepted medium-duty engine with more than 10 million units built to date. And third, we have a proven track record with the ISB. We’ve been building the same configuration with SCR on our Ford Blue Diamond (joint venture in Mexico) since 2010.”

Asked if the adoption of mid-range Cummins engine would result in Navistar dropping its own proprietary engine product, Kozek said, “We’re not exiting the engine business.”

By offering both SCR and EGR medium-duty truck engines, Kozek said customers will enjoy greater choice, which should result in improved medium-duty truck sales.

Meanwhile, Kozek also said customers are responding well to the SCR Cummins engines offered in International’s Class 8 truck line. He said Navistar to date has secured orders for more than 10,000 International trucks powered by the ISX15 with SCR. Combined with more than 4,500 orders for Class 8 trucks powered by Navistar’s own 13L engine, Kozek said the company is showing signs of a resurgence.

“Our Class 8 order share is coming back,” he said, noting its order share for the current quarter is 20.4%, a significant jump from its retail market share over the same period of 14%.

“We’re encouraged by this type of response,” he said.

As for its other medium-duty trucks, Kozek said there’ll be an announcement pertaining to the WorkStar at a later date, and said the ISB isn’t compatible with the Class 4/5 TerraStar.