MONTREAL, Que. -- Designed expressly for the Canadian market where higher gross weights are allowed, Navistar rolled out a 110,000-lb version of the ES spec at Montreal's Expocam on Friday.

The Canadian version of the ES (Efficiency Specification) features all of the same aerodynamic and drivetrain enhancements of the U.S. version unveiled in December, but the engine and transmission are optimized for higher weights. The Canadian version includes a choice of a Cummins ISX15 or a Navistar N-13 engine in a variety of torque and horsepower ratings.

Downspeeding the powertrain is a popular fuel-saving concept with loads up to 80,000 lb gross combination weight, but it's doesn't work well with Canada's higher weight allowances. A 5-axle combination in Canada can gross up to 91,500 lb, while a 6-axle combination can weigh as much as 109,100 lb.

To offset the difficulty in downspeed heavier loads, Navistar, Cummins and Eaton worked to optimize the 16-speed UltraShift Plus LSE transmission to the engine offerings above. The result, says Mark Belisle, president of Navistar Canada, is a powertrain spec that offers fuel efficiency in this higher-weight markets.

"Even fleets running up to 110,000 pounds are interested in fuel economy," he said. "The 80,000-lb SmartAdvantage version was popular with fleets running U.S. lanes but it didn't appeal to heavier operations. The ES 110 is the result of a close collaboration between Cummins, Eaton and Navistar, and it solves a problem for fleets looking for the flexibility to haul heavier loads."

When the ProStar ES was launched in December, Jodi Presswood, vice president of the Navistar Heavy-duty Truck Product Line, said the ES delivers up to 11% better fuel economy than previous versions of ProStar.

"By combining the four elements in the ES spec -- superior aerodynamics, optimized drivetrain, the Performance Engineering Team and the OnCommand Connection system -- we have created a package that changes the landscape in the on-highway tractor market," he said.

Erin Peterson, chief performance engineer for the ProStar ES, says the company did full-scale wind tunnel testing to validate the performance of the package in crosswind situations, which account for a larger portion of aero resistance, on average, than direct headwinds. Studies have shown that on average, anywhere in North America, trucks will encounter a 9- to 10-mph crosswind. So that's what Navistar tested for when developing ES package.

"The package was developed to be the most aerodynamic when it comes to the wind average drag coefficient." Peterson said.

ProStar ES includes a three year subscription to OnCommand Connection, Navistar’s predictive diagnostic system which includes a portal that monitors vehicle performance in real time to ensure maximum operating efficiency.

The ES 110 is available of order now in the U.S. and Canada.