The Trucker — May 2012
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Kenworth T680 Proves Responsive Smooth During MATS Ride-And-Drive
Cliff Abbott

LOUISVILLE, Ky. — Being witness to the unveiling of Kenworth’s newest T680 tractor was exciting, but not nearly as exciting as being asked to test drive one here during the Mid-America Trucking Show.

Doug Siefkes of Kenworth’s public relations firm SiefkesPetit made the pickup at the MATS lot and provided chauffeur services to Peterson GMCKenworth in Louisville where two prototype T680s were waiting.

We drew the day cab model, equipped with a 455 HP Paccar MX engine paired with an Eaton FRO16210C 10-speed transmission.

Kenworth representatives, all wearing golden silk ties in honor of the product launch, provided a few pointers about the unit and one climbed into the jump seat to provide navigator duties.

A pair of textured grab handles made cab egress easy, and the wide door Closed with a satisfying, solid thud.

Adjustments to seat position were quick and intuitive.

The steering wheel uses one control for both tilt and telescope features; the driver simply guides the wheel to the most comfortable position and then locks it in place.

Switches and controls are arranged to be close at hand and large enough for easy operation in the moving vehicle.

One switch was labeled “Pre-Trip” and is designed to operate each lighting system in sequence so the driver can check the operation without multiple trips to the cab to turn lights on and off. The test unit wasn’t equipped with Kenworth’s NavPlus system, but features like navigation, blue-tooth technology and advanced vehicle diagnostics wouldn’t be necessary for our short trip. Climate in the cab is automatically regulated by simply selecting the desired temperature.

Despite a current CDL we knew our driving skills would be a little rusty, but by the time we pulled onto the street, we were already feeling comfortable in the Kenworth.

The Paccar engine was instantly responsive and the shifter for Eaton tranny seemed to find its own way to each successive gear.

We wanted to test Kenworth's claim that the air-assisted hydraulic clutch requires only half the pressure to operate as conventional clutches, and we were pleasantly swprised at how easy it was to push it to the floor. The travel distance has been shortened too, and drivers of shorter stature will appreciate not having to push the clutch quite so far.

The left turn from the dealer lot was rather tight, but an easy chore with the tractor's short turning radius.

Once we got through the light we were able to gear into high range, and the omamp to Interstate 264 provided the opporhmity to upshift through the whole set of gears.

Smooth. Very smooth.

We traveled several miles after merging into the travel lane, providing the opportunity to check out how the truck held its course at highway speed.

The taperleaf spring front suspension didn't provide as smooth a ride as the available air spring version, but it wasn't bad at all. Despite the very responsive steering, the unit tracked superbly with minimal lane wandering.

A navigational mistake provided further opportunity to evaluate the illilt. Two lane changes to the left would have beennorrnally used to avoid exiting the interstate but proved unsafe with the traffic volume present. So, we made our accidental exit and began looking for a safe place to turn around.

The added traffic lights provided more shifting and braking opporhmities. Another accidental discovery occurred when we chose the wrong gear for a gentle turn to the right. The engine RPM were too low and we decided to downshift. But, the low RPM were no problem for the Paccar engine, which produces 1,650 ft.
Lbs. Of torque at 1,100 RPM. The unit accelerated Smoothly without the need a downshift.The test unit was equipped with Bendix drum brakes on all axles, and stops were smooth and sure. In fact, it didn't take a lot of pressure to over brake, but our rustiness behind the wheel was undoubtedly a contributing factor.

Kenworth's "Daylight Door" window design helped make lane changes easier by improving the visibility of the mirrors. We found that the arrangement of the instrument cluster made information easy to find and large numbers made the gauges easy to read. We paid scant attention to the Driver Performance Center during the short test drive, but the value of the display was clear once we came to a stop back at the dealership. The Center yields all kinds of valuable information, including important diagnostics in an easy-to-read fonnat and is a feature we could quickly learn to love.

The T680 met all of our expectations, which were admittedly high after viewing the unveiling and presentations. Kenworth has another keeper.