Enhanced aerodynamics and cooling, plus a well-designed interior make this T600 successor stand out.
The Kenworth T660 is a derivation of the original T600, the industry’s first truly aerodynamic conventional. As such, it offers well-refined aerodynamics, a conveniently designed and roomy interior, improved cooling, and a number of high-tech features.
These include standard halogen headlights with low beams that project 40 percent farther than sealed beams and last 40 percent longer than traditional headlamps. Optional xenon high intensity discharge lighting provides 75 percent more light, and lasts 11 times longer than sealed beams, while providing “an intensity that almost seems like daylight,” says Jason Skoog, Kenworth’s director of market planning and research.
The grille is 5 percent larger than the T600’s for enhanced airflow, yet the aerodynamics have actually been improved. Skoog explains, “We use computational fluid dynamics analysis to find out how truly aerodynamic a truck is. We’ve done extensive studies of airflow with CFD to optimize the aerodynamics of the T660, as aerodynamics are very important in getting good fuel economy.” One ancillary benefit is that the design minimizes splash and spray, Skoog says, “and this gives a very clean view out of the side mirrors.”
The T660’s instrumentation system’s wiring is of an enhanced, multiplexed design. The wiring in the truck features color-coded and numbered wires, which means you can do electrical troubleshooting without needing to trace a wire through the cab and chassis.
The truck also features a GPS system that’s standard with the Diamond interior package. An enhanced driver display, furthermore, offers real-time fuel economy, an ignition timer, on-board diagnostics, gear-engaged display, vehicle system configuration reporting and even an alarm clock. Skoog says that when the chassis is assembled, the air lines are custom cut to the right length for each application, eliminating the maintenance problems that come with excess tied-back, looped or coiled lines.
Other quality features, such as piano-hinged doors and huckbolted chassis components that allow easy repair, enhance the T660’s resale value, he says.
The optional AG130 air suspension is 2 pounds lighter than the taperleaf design, yet gives an even better ride. Many such efforts to reduce weight to compensate for the heavier 2010 selective catalytic reduction system help provide value for T660 buyers, Skoog says.
Owner-operators Angela and Celso Rios haul jet engines for Aviation Express. Although they drive separate vehicles, both have spent time in the cab of their 2010 T660, powered by a 2009 Cummins ISX15.
“The biggest thing I have noticed is that the interior is a lot better laid out and put together than earlier vehicles, even a premium cab like our 2003 W900,” says Angela. “Everything on the dash is within easy arm’s reach and there is a convenient spot for the GPS unit. We have the Pendleton interior trim, a beautiful brown leather which was not an option in the past.” The 86-inch sleeper, she adds, is plenty roomy for the team. “Even though I have not driven it as far as my husband has, I absolutely love the truck. It’s much quieter than our other vehicle.”
She says they bought the T660 because of its aerodynamic design, and it normally gets over 7 mpg, in part because they often haul payloads consisting of one jet engine weighing about 13,000 pounds.
“I love the dash,” Celso says. “It’s beautifully laid out and very driver-friendly. In fact, I like everything about the truck.” He says its ISX15 produces 485 hp and drives through an 18-speed Autoshift transmission with 3.35:1 rears, giving a very low cruise rpm. While their 2003 W900 gets 6 to 6.5 mpg, the T660 hits 7 to 7.5, Celso says. Their use of fully synthetic 5-40 Shell Rotella oil and wide single tires on the drive axles of the T660 probably helps, he says. n
• 122-in. bumper to back of cab
• 128-in. bumper to back of cab with extended day cab (optional)
• Paccar MX
• Cummins ISX15
• Batteries: Paccar starting, dual purpose
• Starters: Paccar 12-volt
• Alternators: 130-amp Paccar brushless, 160-amp Leece-Neville long brush
• Eaton Fuller – 9-, 10-, 13-, 15- and 18-speed manual; 10- and 18-speed AutoShift; 10- and 13-speed UltraShift PLUS
Front: Dana Spicer, Meritor – 12,000 lb. to 14,600 lb.
Rear, single: Dana Spicer, Meritor – 23,000 lb.; 26,000 lb.
Rear, tandem: Dana Spicer, Meritor – 40,000 lb. to 46,000 lb.
• Kenworth – 12,000 lb. and 14,600 lb. 54-in. taperleaf with shocks
• Kenworth – 12,000 lb. and 13,200 lb. Air Ride AG130
SUSPENSION: REAR, TANDEM
• Kenworth – 38,000-lb. AG380; 40,000-lb. AG400; 40,000-lb. AG400L;
• Reyco – 38,000 lb.
• Chalmers – 40,000 lb.
• Hendrickson – 40,000 lb.
• Neway – 46,000 lb.
• 86 in.: Studio AeroCab, AeroCab Aerodyne
• 72 in.: AeroCab Aerodyne, AeroCab FlatTop
• 62 in.: AeroCab Aerodyne, AeroCab FlatTop
• 42 in.: FlatTop
• 38 in.: AeroCab FlatTop
Affected trucks include model year 2008-2018 Freightliner Cascadia and Western Star 4700, 4900, 5700 and 6900 trucks. DTNA says after hard brake applications, the brake light pressure switch may not activate the brake lights with the light application of the brake pedal.