Custom Text

The new Kenworth T680 proves itself in three key areas

By on August 31, 2012

One of my favorite biblical quotations is, “What is required of you, mankind, but that you love mercy, do justly and be humble before God.” Believe it or not, that got me thinking about big rigs. To paraphrase: What is required of you, big truck, but that you provide comfort, enhance safety and operate economically for your owner.

Those three subjects were in mind when I went to Indianapolis to catch up with the Kenworth T680 Tour to test drive the new truck. Let’s take each requirement in order.

Provide comfort

A great deal of effort went into improving the interior space for the T680. The cab, at 83 inches, is wider than the T660 by 10 inches but narrower than the T700’s 91 inches. It’s comfortable, with 23 inches between the seats. The 76-inch sleeper cab widens out to 96 inches in the sleeper area.

To add to the spacious feeling, the passenger seat pivots 180 degrees, positioning its occupant at a rotating tabletop sturdy enough to support the largest laptop computer. There’s a wall mount for a flat panel TV and a shelf for a microwave. Interior storage was increased 65 percent to 60 cubic feet, including a full height wardrobe.

Kenworth’s new GT700 seats automatically adjust for weight, accommodating a body of almost any size and shape.

I took the T680 over multiple railroad tracks, probably a bit faster than was prudent. Obviously, we felt the bumps, but they were quite tolerable thanks to the seats and Kenworth’s air suspension. Driving over broken pavement on a road sorely in need of repair, the truck was comfortable and always under control. All the while, the cab was quiet enough for conversing without raised voices because of extra sound deadening material at the floor and firewall.

The heater/air conditioner has a set-and-forget Automatic Temperature Control. The system stays at whatever temperature is set. One touch of the controls brings up maximum defrost.

Enhance safety

Since most of the stimuli we react to while driving is visual, Kenworth gave the T680 a 50 percent larger windshield. The daylight doors with their cut-away bottom allowed me to see the entire mirror assembly on both sides. That is no easy task, since the convex sections in the aerodynamic housings are 40 percent larger than before.

Visibility is even more of an issue after the sun goes down. Kenworth has, in recent years, developed excellent high intensity discharge xenon headlights. While I didn’t have a chance to do any nighttime driving, the T680 tour had a static display that included simulation of their optional advanced lighting. It’s an option I would take for the safety of improved vision. All other lighting is LED, for intensity as well as long life.

Standard instrumentation has nine gauges including the driver information display. There is room for up to 12 additional gauges, but I would opt for the Driver Performance Center that fits the same dashboard area. The thin film transistor screen can show current truck information, diagnostic data and, if and when needed, pop-up alerts. It can also give situation-specific recommendations to help improve truck performance or economy. The optional NavPlus system includes Bluetooth.

When considering safety, brakes are all important. Bendix Air Disc Brakes are standard on the steer axle, but my test truck had ADBs all around. I did some simulated panic braking, and there was absolutely no hint of any brake pull or steering wander. The T680’s brakes are among the best I’ve ever experienced.

Operate economically

Fuel economy, durability, maintainability and reliability are the keys to economical operations. Kenworth says the T680 is the most aerodynamic truck the company has ever produced by a factor of 10 percent. That alone should result in a 5 percent improvement in fuel economy at highway speeds.

While those needing big power can opt for Cummins’ ISX 15, the standard engine is the 12.9-liter PACCAR MX. It provides up to 485 hp and 1750 lb-ft. Customers who tried the engine in long-haul service report exceeding 7 mpg. The tour truck I drove had the top rated MX and, while loaded close to 76,000, had no problems at all with the grades on the north side of the city. And the Eaton UltraShift PLUS MHP 13-speed transmission made driving a pleasure. I could concentrate on traffic instead of having to match speeds and gears.

The extensive use of aluminum in the cab’s construction, sheet molding compound hood and thermoplastic olefin bumper and fairings resist corrosion and minimize impact damage. Components are easily accessible for maintenance or simple fluid checks. The manufacturing processes should result in a highly durable truck, but for the new cab and engine, only time will tell for sure.

From my perspective, the T680 was easy to drive. It rode well, was quite stable, and handled fast curves and heavy braking with no sense of drama at all. It’s the product of many years of refinement by a highly reputed builder and, frankly, hard as I tried, I found nothing to complain about.

About Road King

For the professional Driver


  1. Jeff Stevens

    November 17, 2012 at 6:34 pm

    I was wondering if it would be possible to have someone supply me with the audio options offered within the Kenworth luxury vehicle lines.

    JJR Acoustics is an integrator and designer of Branded and non-branded audio systems. These systems include amplification and speakers. We can integrate the entire cabin with a complete and enjoyable listening experience for all audio options.

    I would appreciate any information available on the audio options from base level to highest upgrade.

  2. Dan O'Sullivan

    November 23, 2013 at 5:50 am

    The company that I work for switched over to the Kenworth t680. All day cabs. They lease from PacLease,Hickory Hills,Il. After driving mine for a week,i just returned it to PacLease for repairs.The problems? Wandering while driving… inch and a quarter of play in the steering wheel,and when braking….pulls hard to the right.These problems are occurring when bob tailing,and when the heaviest amount of weight on my trailer was at 32,000,weight distributed properly.
    Hopefully these 2 problems can be fixed.I’m sure the braking problem can be adjusted.Not so sure about the steering.I’ve read other posts about the same steering problem and the comments were..”just gonna have to get used to it.” I disagree.Wandering is a dangerous situation that shouldn’t go without being corrected.The steering should be tight.
    Overall…I absolutely enjoy the ride.It’s a great truck.Very smooth and quiet.

  3. Paul Marion

    January 17, 2015 at 3:23 pm

    I work for a company that leases most of their trucks. I have been driving the t680 day cab for a month now. I am really enjoying how quiet it is and how easy it is to maneuver. I do a lot of drop and hooks and short trips during the week. I can easily make it through a 12 hour day with this truck. The clutch is very easy. You appreciate that when you spend a lot of time in stop and go traffic. The cab is much quieter than my previous day cab. I love how the gauges are placed and the roominess of the cab. Their isn’t anything I don’t like. The 15 litre ISX Cummins does take getting used to. The rpms fall very fast. You have to shift quick. I find that shifting at low rpms in the lower gears works best . The ISX pulls great on long grades. Fuel mileage has been around 5.1 to 5.4. Not bad considering the kind of work I do. I can easily scale a 46,000 pound load in a dry box with this. An I.provement over my old day cab. Love this truck.

Leave a Reply

Your email address will not be published. Required fields are marked *