Truck maker Navistar re-launched its “classic” International 9900i tractor and PayStar 5900 SBA vocational models this week featuring the Cummins ISX15 engine equipped with selective catalytic reduction (SCR) technology to make it compliant with heavy-truck emission regulations.

Offered with ratings from 400 to 600 hp with 1,450 to 2050 lb.-ft worth of torque, Navistar said the Cummins ISX15 will be the only engine available for the 9900i, while the PayStar 5900 can be spec’d with either the ISX15 or the OEM’s own MaxxForce 13 SCR-equipped engine.

The truck maker unveiled its Cummins-powered vocational models at ExpoCam, Canada's National Truck Show, in part to highlight the company’s presence north of the border, according to Mark Belisle, president of Navistar Canada.

“Canada can be tough on a vehicle and the power of the ISX15 makes our already rugged vehicles adaptable for any environment,” he added. “And, with more than 7,000 vehicles on the road today, the 9900i and 5900 SBA have proven durability.”

Navistar noted that production of both vehicles began earlier this month, some four months after the first International ProStar highway tractor equipped with the Cummins ISX15 with SCR rolled off the assembly line.