So there I was, westbound on Bow Hill Road in Skagit County, a few hours north of Seattle, wondering if I'd ever find a place to turn around.

I had passed the turn-offs marked on the printed-out map because I wanted to put a few extra miles on this new Kenworth T440 daycab tractor, a recently introduced medium-heavy model. And now I had run off the map.

I was pulling a 48-foot van that made U-turns impossible on this country road, but I figured I'd come across a wide place to do a bit of backing.

Sure enough, on the left there was a lot that apparently was home to several rigs used by local haulers, as a vacant flatbed trailer was parked there. I reversed the rig onto the gravel, paused to shoot a few pics, then backtracked east to known territory. While maneuvering I used all the T440's windows, including its curved corner glass, which added some distortion but were still a plus for outward vision. So was the big window in the cab's rear, the generous DayLite side windows in the doors, and of course the big curved windshield. All were handy when I twice snuck through Edison, a small town with a tight right-angle turn that required using all available pavement to drag the trailer around. (Luckily, there was no other traffic.)

This little excursion was part of a media drive event set up by Kenworth and was staged out of Paccar's Technical Center near Mount Vernon, Wash. The event featured eight Kenworths, one of them the new T700 over-the-road tractor that colleague Steve Sturgess reported on in the July issue of HDT.

Earlier I had wheeled a T800 heavy haul tractor with a flatbed trailer, and later I'd sample a beefy T370 tank truck. Both were easier to drive then this 440 because they had self-shifting trannies - an 18-speed Eaton UltraShift Plus in the 800 and a 6-speed Allison full automatic in the 370. Last summer, back home in Ohio, I had driven a T470 dump and plow truck, another recent medium-heavy offering, and it, too, had an Allison.

Now I had to work a little, because this T440 tractor had an Eaton Fuller 10-speed manual. It required some concentration to manipulate, because its shifting mechanism lacked the pleasurable precision that I usually see in heavy Kenworths. Shifter vagueness in the 440 prevented graceful float-shifting except in some low-range gears, so I soon began double-clutching all the time to get smoother gear changes. (Fleet managers have told me in testy notes that using the clutch is the proper thing to do anyway, but I always try float-shifting because it's a good test of how well the shifter is designed.)

Under the T440's short hood was a Cummins ISL9, a midrange-size 8.9-liter diesel with heavy-duty innards that's based on the ISC8.3. The ISC, private-branded as the Paccar PX-8, is the standard engine in the T440. With the ISL9's base rating of 345 horsepower and 1,150 pounds-feet, this engine was adequate for our gross combination weight of about 60,000 pounds, but like most gear jammers, I'd have liked a stronger rating.

That afternoon I took this rig on another route that included a few moderate highway grades and a traffic-light stop on a hill in Anacortes, on Whidbey Island to the west. We pulled the hills OK and speed dropped to about 45 mph with one downshift. Once I let the ISL lug to 1,000 rpm and it gamely kept going, though speed dropped to 40 mph.

On the upgrade dead start I used 1st (low) gear, but had to ride the clutch a little and feed some fuel to the Cummins to help it overcome the rig's inertia. Ideally I should've been able to start with the torque available at idle speed. Maybe the grade and load put this tractor at the limit of its startability, even with 4.30 gears in the rear end. With more experience in this rig, I'd have been more adept in this situation, and with the optional Allison torque converter automatic I'd hardly have given it any thought except to say, "Thank you, boss, for the autotranny."

In heavier models, Kenworth is suggesting the ISL9 as a lighter-weight and less expensive alternative to the ISX11.9, which replaces the popular 11-liter ISM in Cummins' 2010 lineup. The ISL will no doubt prove itself a long-lived engine, just as previous iterations have in other tractors as well as dump and mixer trucks. But if given the choice, drivers will always opt for a bigger block, or at least a higher rating. Tops with the ISL9 is 380 horsepower and 1,300 pounds-feet.

One thing this ISL provided was a healthy dose of sound and vibration right in its main operating range, from about 1,400 to 1,700 rpm. I don't know what effects, if any, the shuddering had on the driveline. But the vibes and growls told me the engine was working. I actually found it enjoyable, kinda like the good ol' days of big 855-cubic-inch NTCs. Cummins needed that much engine in the 1970s to produce what this 544-cubic-inch ISL now makes, and this engine emits absolutely no smoke or odor. Behold the wonders (albeit expensive) of the 21st century.

This T440 was set up for regional hauling, with a pair of 75-gallon fuel tanks that give it range for a couple of days of hauling. It's a "heavy 7," as engineers at Kenworth and sister company Peterbilt like to say. It had Dana Spicer axles and Kenworth-made suspensions of 12,000 pounds front and 23,000 rear, the latter an AG230 air-ride, adding up to 35,000 pounds. That's a ton into Class 8, and because of that the tractor's buyer will have the civic duty of paying the 12 percent federal excise tax. However, along with the heavier components comes greater durability and longevity that presumably would offset the FET over the vehicle's lifetime, not to mention providing the capacity needed to haul required loads.

Decent accommodations await the driver, thanks partly to the Extended Cab option that adds about 6 inches of very useful leg and belly room. A tilt-telescoping steering column put the wheel right where it's needed for almost anyone. The interior was nicely trimmed and had a real-truck look; the dashboard had the characteristic flat design of most Kenworths, but the instrument panel is more midrange style with fewer gauges, and the light switches are at the lower left instead of on the upper right, as on heavy T's and W's. Between the seats was a center console with a bin big enough for file folders and a compact laptop PC. All in all, it's a nice place to work.

By the feel of it, this T440 should last a long while. It's got a strong chassis and the stout aluminum cab that's common to all of Kenworth's T- and W-series conventionals. These cabs are air-tight, so you have to slam the doors unless you crack open a window, and they latch with a satisfying klunk!

There are many details of design and manufacturing that Kenworth uses to earn its premium reputation, and this latest model should live up to it.

From the August 2010 issue of Heavy Duty Trucking.