LOUISVILLE -- Kenworth designers have turned to the trailer part of their T680 Advantage rig, integrating the smoothly styled tractor's aerodynamics into the lines of a 53-foot Utility van. The tractor has mechanical and electrical equipment meant to save fuel, but reducing air drag across the entire vehicle is almost as important, they said.

On display outside the South Wing of the Kentucky Expo Center at the Mid-America Trucking Show, the Advantage rig looks like it's slipping through the air even while it's standing still. 

"To gain the optimum in vehicle fuel economy, the trucking industry must view aerodynamics, powertrains, drivers and trailers in concert.  They all must be integrated to maximize vehicle fuel efficiency," said Kevin Baney, Kenworth chief engineer, in a statement. "The T680 Advantages shows the industry what's possible when you integrate the total vehicle."

The T680 tractor is Kenworth's most aerodynamic model and has received EPA SmartWay designation, so is the logical one to use in the Advantrage program, Baney said. Last fall it was picked by a panel of truck writers (including yours truly) as the 2013 Heavy Duty Commercial Truck of the Year in a competition sponsored by American Truck Dealers.  

"The MX-13 engine is paired with an Eaton UltraShift Plus automated manual transmission to maximize fuel efficiency," he said. "Studies have shown that drivers may influence upwards of 30% of fuel economy numbers, so reducing the driver variable can significantly improve a fleet's mpg."

The tractor has several electronic features to aid to fuel economy, as well as an enhanced aerodynamic package. The trailer was modified to match the tractor. Trailers in general have come a long way in helping tractors and their drivers achieve good fuel mileage, and this one was got many hours of fluid dynamics studies so it closely matched the tractor's lines. The van's height, tandem location and rake, or roof angle, were considered.

A Laydon nose fairing fills the gap between the tractor and front of the dry van to shield the trailer from the negative impacts of a crosswind. Its open design allows access to air and electrical connections, but on its own it can save up to 3% at highway speeds, Baney said.

(Nose Cone has a similar product called Side Burns; it's a "mustache" in the lingo of Jim Park, our equipment editor who shot these photos.)

The side skirts are Utility's own product and have been SAE-tested to provide a 5% improvement in fuel economy. Completing the package is an ATDynamics TrailerTail, which has been tested to provide more than 6% betterment. (The three items do not together yield a 14% improvement, he notes.) 

These aerodynamic traler parts may be purchased in the aftermarket. Side skirts and nose fairings are available at Kenworth dealers.