International HX620 Is a Premium Ride

Aug. 24, 2016

When Navistar was assembling the Cat Truck for Caterpillar, there was a substantial difference between it and Navistar’s own International PayStar on which the Cat Truck was based. The CT series had a more substantial look and feel, and was decidedly upscale, just as Caterpillar wanted. When Navistar introduced its new HX series early this year, it was as though it was planned to succeed the Cat Truck, even though Navistar people say they didn’t know that Cat was about to cancel their program.

So, to the guys who bought Cat Trucks for what they were and for the bragging rights that came with them: Check out the HX, because it’s almost the same vehicle. If “International” isn’t something to brag about, be aware that it’s one of the oldest and proudest names in the automotive industry. And get smug because an HX will cost maybe $10,000 less than a CT would have. That’s according to a salesman with a dealer that sold both brands; I met him at the unveiling of the HX series in Las Vegas last February.

International HX620 Test Set

Truck: Conventional-cab vocational straight truck, aluminum cab, Metton hood, BBC 120 in., w/ 12x3-3/4x1/2-in. main frame rails & 150,000-lb. front tow pin

Engine: Cummins ISX15, 14.9 liters (912 cu. in.), 500 hp @ 1,800 rpm, 1,650 lb.-ft. @ 1,200 rpm, w/ engine brake

Transmission: Eaton UltraShift Plus FO-18E318B-VXP (Vocational Extreme Performance) automated 18-speed double overdrive

Front axle: 20,000-lb. Meritor FMS-20-133A w/ Sheppard M100/M80 dual steering, on 20,000-lb. parabolic leafs & shock absorbers

Lift axle: 20,000-lb. Watson & Chalin SL2065 Tru-Track steerable pusher

Rear axles: 46,000-lb. Meritor RT-46-160P w/ 4.10 ratio, on 46,000-lb. Hendrickson HMX 460-54 mechanical

Wheelbase: 232 in.

Brakes: Meritor Q-Plus S-cam w/ Bendix ABS

Tires, wheels: 425/65R22.5 Continental 465 front, 11R22.5 Continental 491 rear, on polished aluminum discs

Fuel tank: Single 100-gal. 26-in. diameter polished aluminum

Body: 22-yd. Ox 19-ft. smooth-side Ultra-Lite steel dump

And you couldn’t get a Cat Truck with a 15-liter diesel, only a 13-liter Navistar motor that was painted yellow. The International HX comes with Navistar’s own N13, like the CT had, and Cummins’ ISX15 (soon to be the X15). Our test truck had the big Cummins, which executives said made Navistar’s return to the premium vocational market possible. There are some duties where nothing but a big-bore engine will do. Caterpillar people knew that and were frustrated because they no longer made truck engines and there was nothing left but the big Cummins. Aside from very slow sales, that was another reason to drop the Cat Truck.

It took a while after the HX introduction in Vegas for me to get a drive of a truck. It happened in mid-summer at the Navistar Proving Grounds in northern Indiana, west of South Bend. There I met up with Chad Semler, the HX’s product marketing manager, and we proceeded to a conference room where we got a safety briefing from the grounds’ chief engineer of operations, Brian Jacquay. He didn’t smile much as he pointed out some of the areas we’d be driving the truck, so I knew that he was serious about not wanting anything untoward to occur. It didn’t.

Semler did a walk-around on the truck and answered my questions. For instance, what does the designation mean? HX means “Heavy eXtreme,” for the anticipated duties the vehicles will see. The “6” in this truck’s designation means a setback steer axle, and the “20” denotes a 120-inch bumper-to-back-of-cab (BBC) measurement. The other ISX15-powered model is the HX520, with the same BBC but a set-forward steer axle, indicated by the “5.” Their long hoods are needed to accommodate the big-block engine; that big hood might be heavy, but it’s easy to open and close, thanks to long shock-type supports. As viewed from the driver’s seat, an elongated rib on top frames the forward-facing International orange diamond name plate, and serves as an aiming stake to line up the truck with the right edges of pavement.

Two shorter-hooded models are the HX615, with the “6” meaning a setback axle and the “15” indicating a 115-inch BBC, and the HX515, with the same BBC and a set-forward axle. Both use Navistar’s 12.4-liter N13 diesel.

Basic styling for all HXs is big and bold, like a Cat Truck. The HX, too, is based on the PayStar, which will be phased out. Even with their roomy aluminum cabs, PayStars I’ve driven in the past have been bare-bones trucks, and I’ll bet drivers of dumps, mixers, and other heavy work trucks will be happy to see the nicer HXs show up in fleets. Semler said the first HX delivered to a customer went to a logger in British Columbia, Canada.

The chassis includes 12-inch-high, 1/2-inch thick main rails with 3-3/4-inch webs, which is stiffer than many frames using reinforcements, he said. Up in the cab, one Cat Truck feature used in the HX is the combination speedometer and tachometer, along with a deluxe-looking two-panel wrap-around dashboard. 

This HX620 was nicely appointed, with chrome and other polished-metal pieces brightening up the exterior. Inside it had a deluxe trim package that included leather-covered seats, brightly rimmed gauges, and attractive paneling on doors, walls, and ceiling; a simpler package is also available. Noise was well dampened, especially during loops around the 3-mile oval track where we cruised at 65 and 70 mph, and even as we banged and bounced over the endurance courses. Air-ride seats and twin air bags at the cab’s rear corners insulated us from much of the jolting. Wiring was not the Diamond Logic multiplex system but a less complex “point-to-point” setup, Semler said. 

I followed his directions as I steered the HX over a gravel trail and pavement with rumble strips and other rough surface features. One is an “undulating” asphalt course originally laid out by engineers from Studebaker Corp., the car and truck maker that established the track in 1926. Early last year, Navistar bought the 675-acre facility from Bosch, its most recent owner, and has moved formal course testing once done at the old technical center in Fort Wayne, Ind., to this sprawling complex. It’s only a 90-minute drive from the company’s headquarters in Lisle, west of Chicago, and not much farther from the engine works at Melrose Park, Ill.

The return of Cummins diesels and use of its exhaust aftertreatment systems for Navistar engines has helped the truck maker increase truck sales, cut deep losses, and return to modest profitability early this year. Better financial performance also gave the company the means to buy the proving grounds. The huge facility is a profit center for Navistar, and fully 70 percent of the testing here is classified as “outside,” Jacquay said. That includes military contracts and operations by component suppliers and other truck builders. None of that was in sight in the areas we used, partly because most activity had paused while drivers and technicians ate lunch. 

With a 500-horsepower rating, the ISX15 in this truck was way more than adequate to propel the truck and its load of about 10,000 pounds of gravel. The engine ran through an 18-speed Eaton UltraShift Plus, which handled much of the work of driving the truck. With 18 ratios, it had good startability as well as high-speed capability, with the tach needle far below redline. Acceleration was brisk, with the tranny skip-shifting a lot at lower speeds. I noticed that the UltraShift let the engine rev to 1,900 and 2,000 rpm in the lower gears, so I used the up arrow on the selector pad to prompt earlier upshifts. Semler said that the transmission was programmed for vocational duties, and most customers prefer higher revs for better performance over rough terrain and while climbing grades. So then I left the selector alone.

You’d expect a setback steer axle to allow good maneuverability, and this one did. Wheels cut by up to 40 degrees in left and right turns, even with wide 425-series tires supporting its 20,000-pound rating. This means the truck can ably move through sharp corners and around obstacles on job sites. The tandem drive axles rode on a Hendrickson HaulMaxx mechanical suspension, which is standard on the HX; ride was acceptable, but probably would’ve been better with one of the air-rides available. A single pusher axle added capacity to the 10-wheeler; this “tri-axle” configuration is the norm in Indiana, Pennsylvania, Alabama, and certain other states.

This driving experience was shorter than others I’ve done, but covered a variety of terrain and road surfaces and showed what the HX is capable of. I saw solid, agile handling; good maneuverability; decent comfort and ride quality; and commendable quietness. If it proves to be as reliable as it is handsome and comfortable, the HX will be a winner for Navistar and the people who buy and run the trucks.