The optional folding armrests allow easier access to the sleeper.
Kenworth launched the T600 in 1985, when its aerodynamic styling was both new and somewhat revolutionary. Its successor – the new T660 – hit full production last fall. Kenworth says it uses less fuel even than the T600, mostly due to cutting-edge aerodynamics.
A Kenworth drive test afforded me the opportunity to test two differently spec’d T660s. At Paccar’s Technology Center near Seattle, I climbed into a silver pearl T660 Aerocab with an 86-inch sleeper and Pendleton interior, pulling a fully loaded dry van. The power plant was a 475-horsepower Cater-pillar C15 with 1,650 lb.-ft. torque, hooked to an Eaton 13-speed Ultrashift fully automatic transmission leading to 3.55 Dana DSP40 drive axles and Bridge-stone 295/75R22.5 tires.
I was southbound on I-5 when snow reduced visibility to less than 100 feet. The roads were too warm to freeze, so I continued south, albeit well below the speed limit. Turning around at Exit 215, I overshot the left turn onto the northbound entrance ramp by a few feet. While making the hard left, I found that the T660 cuts a sharp turn if necessary. I expected the front wheels to reach the paved shoulder, but the last turn of the steering wheel brought the T660’s front end around sharply, and the truck entered the ramp with all wheels between the sidelines.
I pulled over for a map check, then drove north and got off at Exit 221. After missing a turn that wasn’t on the map, I ended up on state Highway 532 westbound until spotting a turnaround opportunity in a country-club parking lot. The T660 politely idled in, smartly pivoted 180 degrees on its trailer tandems and rolled back out onto the highway.
When you miss a turn, it helps to be in a truck that minimizes the consequences of your error. The 660’s defroster melts snow off the windshield; it has good wipers and mirror heaters for maximum visibility; it has sure-footed maneuverability in close quarters, especially when fully loaded; it’s responsive in suburban traffic; and it has a tight turning radius.
My next highway test-drive was a T660, also silver pearl, but with a 72-inch sleeper and a 500-hp Cummins ISX, making 1,650 lb.-ft. of torque coupled to an Eaton 14-speed Ultrashift. This route was simpler: all on state Highway 20, a twisty, two-lane road that approaches the coast. Maneuverability, visibility and responsiveness were in demand, and a well-designed truck made this work easier.
