Issue link: http://read.dmtmag.com/i/71813
Powertrain The T680 is available with the Paccar MX engine as the standard position, but then there's the Cummins ISX in its established 15-liter configuration. Also released is the 11.9-liter ISX, which Cummins says shares much of the design philosophy of its bigger counterpart. It is, though, quite different in just about every respect. The 11.9 has seen significant development as a natural gas engine and provides an interesting alternative fuel power unit for the new truck. The Cummins ISX at a 485 hp rating is a 1,650 It is essential to specify the swivel passenger seat to gain maximum advantage of the flexibility designed for the T680's seat and table. lb.-ft. engine, so it offers good performance and excellent fuel economy. Coupled with the 13-speed Ultrashift, it is a very flexible package that should please operators. The transmission is an overdrive automated In the same way as the T700 picked up strong styling cues from the T660, the new T680 is clearly recognizable as being from the same family. It's designed to have wide appeal with its extra accommodation over the T660 without the vastness of the T700 and a comprehensive rethink of an all-new interior. In the concept phase, more than 850 drivers were interviewed and asked to sit in an adjustable cabin space. The goal was to optimize it for a wide range of driver types and sizes, says Jim Bechtold, Kenworth director of product planning. The resulting 680 is available as a daycab or as a fully integrated sleeper. ENGINEERING The T680 cab features highly tooled door opening pressings and triple- sealed doors that guarantee excellent fit. With a pressure relief valve included, closing the door requires only the slightest effort. Styling lines in the panels guarantee integrity of the cab and structural stiffness; a deep side window and excellent new mirrors provide great visibility. While it may appear a little funky when looking at the windshield top corner and the side window line, the extra tall windshield brings light into the cab and enables a view of overhead traffic lights. The aerodynamic design was achieved with Magna International, claimed to be the biggest supplier of automotive components. The T680's aerodynamic shape benefits from a sculpted full-height roof, an optimized bumper and hood, full-height side extenders, cab/sleeper-to- fairings closeout panels, chassis fairings extenders and flush-mounted lighting. Kenworth says it adds up to a 10 percent enhancement in aerodynamics over existing models, including the T660. The T680 was engineered with 65 percent more storage capacity than the T660 with a 50 percent larger windshield and 40 percent less interior noise. Door openings are 30 percent larger. The hood is wider and lower than the T660's. Headlights are dual halogen (standard) with optional HID Xenon lamps, which Kenworth says creates the industry's best forward lighting. The hood is in three parts for with a top gear ratio of 0.73. With the 22.5-inch Michelin rubber turning 511 revs per mile, the overall gearing gives the truck a tall 1,275 rpm at 60 mph, or 1,380 at 65 mph. Backing it down to 62 to gain the best fuel economy sees the engine turning at 1,320 rpm, way down the speed range but still with the ability to pull small grades without downshifts. And with the automated transmission in control, the driver doesn't need to be concerned about that in any case. Cummins ISX 15 easy, less costly repair. The bumper is split for similar reasons. Along with good side and rear visibility, the forward view is enhanced with a steeply sloping hood and carefully angled "A" pillars for minimum intrusion into the field of view. Mirrors are cowl-mounted. JULY 2012 OVERDRIVE 51