Navistar unveiled the fourth version of its severe-duty International HX series, the HX520, with a forward-set steer axle, a 120-inch bumper-to-back-of-cab measurement and Cummins' ISX15 diesel.  

Shown at Truck World in Toronto, Ontario, the new model will serve the heavy haul tractor, construction dump and platform stake/crane markets, the manufacturer said.

The HX premium vocational series and its first three models were introduced at the 2016 World of Concrete trade show in Las Vegas in February.

"We have been generating a steady stream of truck orders since we launched the HX series and that number is growing by the day," said Jeff Sass, Navistar’s senior vice president, sales and marketing. "We expect demand for the HX series to continue to grow with the HX520 debut."

HX features include a frame with 12.5-inch-high by 0.5-inch-thick rails delivering 3.5 million resisting-bending-moment strength at 13% less weight than a frame using 10-inch rails with inserts, he said. It has a 40-degree wheel cut with 425 series tires for good maneuverability, and a new DriverFirst cab air suspension for a comfortable ride.

The four models vary in configuration and can service a variety of vocational tasks, Sass said. The three models previously unveiled at World of Concrete, and their primary applications, are:

• HX515, a 114-inch BBC set-forward-axle straight truck for vocations including concrete mixer, construction dump, refuse/roll-off and crane.

• HX615, a 115-inch BBC set-back axle truck or tractor for construction dump, concrete mixer, platform stake/crane and refuse/roll-off.

• HX620, a 119-inch BBC set-back axle truck or tractor with for heavy haul tractor, for construction dump and platform stake/crane.

The HX515 and the HX615 are powered by Navistar’s N13 diesel, while the HX520 and HX620 use Cummins’ ISX15 diesel.