Kenworth’s T600 celebrates 20th anniversary at GATS

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Updated Jun 24, 2020

Kenworth is exhibiting a new, fuel-efficient, 2006 model T600 at this week’s Great American Trucking Show, now being held at the Dallas Convention Center through Saturday, Aug. 27.

The T600, celebrating its 20th anniversary this year, has evolved and changed significantly over the past 20 years, undergoing numerous aerodynamic and creature-comfort updates. According to Kenworth, today’s T600 has a 26 percent lower drag co-efficient as compared to the very first T600.

The story of the Kenworth T600 began nearly 30 years ago. In 1976, Paccar director of research and development Larry Orr, who passed away in 2001, and a small team created wood and wax models, testing different shapes and configurations, often at the University of Washington’s wind tunnel in Seattle. Later, in the early 1980s, Orr’s group built a prototype and ran tests at the Paccar Technical Center. “It confirmed the whole idea of aerodynamics and fuel economy,” he recalled in a 1997 interview.

While the Kenworth T600’s sloped hood drew most of the attention, the truck was loaded with other innovations. A set-back front axle allowed for easier front axle loading. New 64-inch taper-leaf springs provided a much improved ride, and the turning radius was 23 percent less than on other conventional trucks. The new design reduced splash and spray by 50 percent, to the great benefit of other vehicles on the road.

But the truck’s biggest selling point was economy. “The fuel economy numbers we got in wind tunnel testing were pretty significant,” Orr said, “and we were confident those numbers would prove themselves – but we had to do some real-life testing to confirm our calculations.”

The next step was testing a standard straight hood conventional tractor and computing its fuel use at the Paccar Technical Center test track. Then the hood was removed and the truck was reconfigured like the Kenworth T600, while leaving the power train and other components as is. The T600 turned out to be 22 percent more fuel-efficient than the straight hood conventional.

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The new truck was introduced at Kenworth’s 1985 dealer meeting. According to the truckmaker, the T600’s fuel economy numbers were too substantial to ignore: Its first users saw a significant reduction in fuel bills, which accounted for 20 to 25 percent of operating costs. By year’s end, T600 sales represented more than 40 percent of Kenworth’s new business.

While the principal testament to the T600’s success has been the number of orders for the truck since its introduction in 1985 – more than 108,000 have been sold – Kenworth also received the U.S. Department of Transportation’s National Award for the Advancement of Motor Vehicle Research and Development, in recognition of the Kenworth T600’s advancements in safety, energy savings and reduced environmental impact.

The T600 continues to make Kenworth history today: It recently became the 250,000th truck produced by Kenworth’s plant in Chillicothe, Ohio, and was one of the initial Kenworth 2006 Class 8 model trucks featuring a brand new cab interior.

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