International pulled the wraps off the sleeper version of its new severe-duty truck in September at the North American Commercial Vehicle Show in Atlanta, the third in a series of unveilings over the past year, following the new LT and RH Series models. The HX officially took its first bows at the World of Concrete show in Las Vegas last February. While the HX doesn’t differ a whole lot visually on the outside from the tried-and-true PayStar it replaces, the new truck follows the same trend as the LT and RH with aggressive and highly focused upgrades under the skin, including greater attention to driver comfort and productivity, enhanced powertrain offerings, and a future-ready platform that is fully enabled on the telematics front and capable of adopting more advanced vehicle communications systems as they come available.

At International’s test track outside of South Bend, Indiana, in October, I was able to take a brand-new HX tractor with a loaded flatbed trailer on an off-road course designed to showcase the durability and ruggedness of International’s heavy- and medium-duty vocational trucks. There were no paved segments on this course, so evaluating the truck’s behavior in an on-highway setting was clearly impossible. But I was able to get a solid sense of the design philosophy that went into the HX, as well as an excellent feel for how the truck performs in fairly grueling off-highway conditions.

The HX bears more than a passing resemblance to the PayStar, but an overall design template with the new LT and RH models is clearly in evidence, too. The result is a distinctively bold look that sets the truck apart as a rough-and-ready severe-duty hauler. You can see the wide, linebacker stance the truck has, along with the aggressively styled nose and pronounced chrome grille up front. Walk closer, however, and you see right off that this old-school look is combined with a sharply sloped front hood that provides outstanding views forward and down from the driver’s seat along with improved aerodynamics at highway speeds.

Solid and smartly placed handholds, combined with broad, diamond-cut steps, make climbing up into the cab a safe and easy job. Once you’ve settled into the driver’s seat and scanned the cab interior, the most visible set of HX improvements jumps out at you.

That’s because it is inside the cab where International engineers focused a good portion of the new technology and ergonomics designed into the new HX Series. Many of the changes were based on the extensive interviews International designers did with truck drivers from all over the country as they began to work on its new lineup of trucks. But International had a definite card up its sleeve when it came to delivering on those interior enhancements on the HX.

That ace in the hole was the cab left over from the CT-Series of Class 8 trucks, which were produced by Navistar until Caterpillar decided to take over production of the vehicles in 2015. International was able to keep the Caterpillar-designed cab interior as part of the agreement to end the partnership between the two companies, but it made substantial enhancements of its own based on driver feedback.

The result is a comfortable, thoroughly modern interior, set off with brilliantly lit instruments, gauges and control panels, including modern graphics and a driver information system. As noted, views from the driver’s seat are outstanding. And I really liked the overall placement of the steering wheel and views over the front dash. Taken as a whole, the HX really has more of a “big pickup truck” feel when you’re sitting behind the wheel, overall size and aggressive stance aside.

I started my career covering construction equipment and always felt like the Cat CT Series cab nicely emulated the company’s ergonomics philosophy, honed over decades of designing machinery. The HX Series cab builds on that with an extremely comfortable interior and switches placed within easy reach. All switches and knobs are also designed to be readily identifiable by feel and can be manipulated by gloved hands — more nice touches for drivers who work on construction sites all day long.

I once said I thought manual transmissions would eventually be relegated to severe-duty trucks only. But in fact this truck was equipped with an 18-speed Eaton-Fuller automated manual transmission, with a big Cummins X15 diesel putting out 565 hp up front. Here, another holdover from the Cat CT Series comes into play: International has taken Cat’s already excellent sound-dampening measures even further to create a severe-duty cab that is as quiet on a rough off-road course as one of its long-haul tractors is cruising along at highway speeds.

The road course itself was a mixture of cobblestones, ruts, twist and flex and gravel stretches, and the HX Series gobbled up each one and left it behind eager for more. The truck drove very well and proved easy to handle, despite its size and the long flatbed trailer behind us. The Eaton-Fuller AMT handled everything from creep mode to ruts with ease, and along with the Cummins X15, accelerated smoothly and quickly on the one long stretch of gravel road I was able to approach highway speeds on. Anyone who’s ever driven on gravel roads knows well that incessant roar that swells up from underneath the vehicle. But in the HX that roar was reduced to a mild rumble. Even on the tougher parts of the course, going across ditches and over alternating speed bumps and cobblestones – sections that bring out the worst in cab interiors with lots of bumping, groaning and squeaking — the HX interior remained remarkably quiet, with everything battened down in place and staying there, no matter how much the truck jerked and swayed its way through the off-road course.

If you’re a heavy-hauler or a severe-duty fleet with an eye toward retaining drivers and moving into the telematics era, then the International HX is certainly worth a test drive. The truck is tough enough to deal with harsh off-road conditions and do so while giving drivers a smooth, comfortable and safe ride.