Kenworth measures engineering advances in productivity gains

By necessity, truck engineers live in the future. So even though we've just begun 2001, Jim Bechtold and his engineering team at Kenworth have been focused on 2002 for some time already. That's when the next round of tighter diesel engine emissions standards takes effect.

The good news, says Bechtold, is that despite worries that fuel economy could take a major hit, they've come up with solutions that not only meet EPA requirements, but do so without hurting fuel economy.

The major problem was the high heat rejection anticipated with 2002's leaner burning diesels. “We initially thought we'd have to increase cooling capacity by 30 to 40% to handle the heat, which would create increased aerodynamic drag and lower fuel economy,” says Bechtold. “As we began looking at heat rejection requirements, we developed a model of use that showed us we'd only need that much (cooling capacity) at high ambient temperatures — over 100 deg. F — in high altitudes under full load.”

Over-the-road equipment only sees that combination of conditions about 3 to 4% of its total operating time. “Production of pollutants is directly related to the amount of fuel that goes through an engine,” Bechtold explains. Through use of an EPA-approved auxiliary engine control device to handle those rare high-heat conditions, Kenworth's engineering team has found that it can save fuel, and thus reduce total engine emissions, by avoiding radically larger radiators and their higher aerodynamic drag.

Electronics are the common denominator in a number of other areas that have KW's engineering staff excited about the future. “The use of electronics (in truck designs) is clearly growing,” Bechtold believes. “We think that they will bring a tremendous advancement in truck productivity.”

While electronics are already established in the eyes of engineers as part of smart powertrain components, Bechtold and his team are now focused on systems that use the information that's beginning to flow over heavy-truck data buses “to help drivers and their fleets operate more efficiently,” he says. “Electronics have the potential to reduce operating costs, not by cutting fuel use necessarily, but by increasing the percentage of time trucks are actually moving goods to destinations.”

While fleets will see the fruits of electronics development in advanced navigation and active safety systems, there are less obvious, but potentially just as important benefits being driven by new electronic tools for truck engineers, Bechtold adds. “Computers now give us the ability to simulate interior spaces,” he says. “We can use virtual reality to help people experience the driver's environment without a truck. That allows us to quickly and easily do robust and complex studies on how drivers react to various (ergonomic) packages.”

Computer simulation has also helped Kenworth's engineering staff move aerodynamic design work from wind tunnels and beyond “empirical seat-of-the-pants techniques,” Bechtold says. “With computer fluid dynamics tools, we can look at airflow over, under and through the truck. It gives us a window into aerodynamic flow around the truck that we never had before. You'll see the results (of this research) in the next three years or so.”

But whether it's emissions, electronics or some other engineering advancement, “the bottom line for us is to improve the utilization and productivity of the truck,” Bechtold says. “Our goal is to let owners haul more by lowering weight, improving uptime and increasing overall efficiency, while still maintaining the eye and driver appeal Kenworth has always been known for.”

Each month this new column will look at emerging truck technology issues through the eyes of some of the industry's leading engineers.

Name: Jim Bechtold, chief engineer, Kenworth Truck Co., a division of PACCAR Inc.

Background: Bechtold has held engineering and quality positions with PACCAR since joining the company in 1975. Before taking his current post at Kenworth's headquarters in Kirkland, Wash., in 1997, he spent five years as general manager of the PACCAR Technical Center in Mount Vernon, Wash. A registered professional engineer, he holds a BS in Mechanical Engineering from Cornell University and an MBA from Seattle University.