Next-gen T680’s a looker, inside and out

March 26, 2021

Tom Berg


There’s a lot to like in Kenworth’s next-generation T680 road tractor, as a few of us CDL-holding reporters discovered during a March 18 event out of Renton, Wash., the site of a KW plant and its research and development operations.

Officials set up a pair of rigs for us to drive around a 42-mile loop covering city streets, state highways and a stretch of Interstate 405 east and south of Renton. One tractor was a plushly appointed T680 with a 76-inch integrated sleeper, and the other was a bare-bones (except for leather-trimmed seat covers) daycab. Each pulled a 53-foot van. The sleeper tractor carried truck and test parts that brought the gross combination weight to 67,000 pounds, we were told. I drove ’em both.

Of course I liked the sleeper-cab tractor for its comfort and quietness, but the daycab maneuvered and accelerated better because of its shorter wheelbase and lower weight at 30,000 pounds GCW with its empty trailer.

Paccar diesel, automated transmission

Both tractors had Paccar MX-13 diesels set at 405 horsepower and 1,750 lb-ft – an almost anemic rating by today’s standards – running through Eaton-made, Paccar-branded 12-speed automated manual transmissions. The self-shifting transmissions made driving crazily easy. At low speeds they changed gears a little slowly, but they always chose the correct gear for any occasion. The only faltering I experienced was during an acute-angle right turn when the engine brakes kept pulling on the driveline, slightly confusing the transmission’s brain. I should’ve turned off the Jake Brakes as I slowed down, but I did so the second time I made that turn and the transmission was fine.

The automated transmission’s driver interface was a stalk on the right side of the steering column. A twist switch read D, N and R, and for forward travel I just left it in Drive and let the transmission ably do its thing. The stalk also controlled the Jake Brakes with up and down detents: all the way up was off, and three settings downward engaged the three levels of braking performance. The transmission downshifted as the truck slowed, allowing the Jake Brakes to keep developing good retarding power. With the stalk pulled down for full retarding, it is sometimes blocked from view by the steering wheel’s right-hand spoke.  Once you know the stalk is there and what it does, you can operate it by feel. A torque-assist feature lessens arm strain and tends to keep the wheel straight and the truck centered in its lane, but it won’t steer the truck on its own. It did not interfere with my spinning the wheel while maneuvering.

Aerodynamic design on T680

Compared to the outgoing T680, the next-gen model has swoopier styling with a lower nose and smaller grille, made possible by a narrower but deeper radiator, explained Brian Lindgren, Kenworth’s R&D director. New LED headlamps include eyebrow-shaped running lights. Fenders and lower skirts are re-sculptured, and fenders mount blade-shaped turn signals so folks alongside can plainly see the driver’s turning intentions. In modern aerodynamic terms, it’s a handsome vehicle, but if you’re a “large car” guy or gal, you’ll still want a traditionally styled Dubya 9 (either the W900 or newer W990, or maybe something else from somebody else).

Digital dash

Inside the new T680, staring right at you, is a digital dash that you might or might not like, but probably will after you’ve spent some time behind the wheel as we did.

I told Lindgren and Kenworth’s design director, Jonathan Duncan, that I had disliked the idea of an electronic dash because I know that someday it will malfunction and will be expensive to repair or replace. Then again, I’ve seen 30-year-old luxury cars with digital dashes that still work, and while trucks are subject to far more vibration, modern trucks ride fairly smoothly to protect their contents. And I ended up liking the T680’s colorful screen because it’s easy to view and read and presents a lot of information that a bank of mechanical gauges cannot show nearly as effectively. (Peterbilt, KW’s sister company, uses the same screen but has a different display design, Lindgren said.)

The digital dash can be configured in many ways. You can start from a very basic speedometer-tachometer and little else. Then you can go to the speedo-tach plus multiple engine- and component-condition gauges displayed within wing-like lines on either side of the main two gauges, and you can change what’s in the virtual condition gauges. You can set up the screen with your favorite gauges and pieces of info, and the LED screen will display that way each time you fire up the truck. You can also change it while sitting still or, to some extent, while underway. Duncan stood on an outside step and showed me how switches on the spokes of KW’s Smart Wheel control the screen; one is a small wheel used to scroll through lists of available info. “Well, I’ll be,” I said repeatedly. You might, too, when you see and examine a next-gen T680.  LL

Kenworth’s next-gen T680
Swoopy lines and a low nose mark Kenworth’s next-gen T680, This one has a 76-inch high-roof sleeper. The narrow but deep radiator allows for a small grille. The tractor has a Paccar powertrain, Bendix disc brakes all around, and a wheelbase of 231 inches. (Photos by Tom Berg)


Kenworth’s next-gen T680 dash
Amber-accented leather seats look good and are nicely cushioned. Smart Wheel’s spoke-mounted switches control the colorful digital dash, among other things.


Kenworth’s next-gen T680 interior
Amber-accented leather seats look good and are nicely cushioned. Smart Wheel’s spoke-mounted switches control the colorful digital dash, among other things.


T680's new sleeper-cab side extenders
Among T680’s new features are sleeper-cab side extenders that fold out for easy access to the air and electrical lines. When closed, they lock in place.

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Tom Berg worked his way through college by driving trucks. Since 1978, he’s been writing about trucks and trucking. He holds a Class A commercial driver’s license and drives trucks as part of story research. While semi-retired, Berg still writes about semis as a contributing editor at Land Line.