Check out this beauty.. with better fuel economy, the best of both worlds! Navistar Rolls out New Efficiency Spec for ProStar

International Truck unveiled a new fuel efficiency package for its ProStar model, called ProStar ES. Short for efficiency specification, the ES package combines enhanced aerodynamics with improved powertrain efficiency and Navistar’s proprietary OnCommand Connection remote diagnostics system. "The ProStar ES is a package, an ecosystem, if you will, developed by our performance engineering team to deliver maximum fuel economy," says Jodi Presswood, vice president of the Navistar Heavy-duty Truck Product Line. The SmartAdvantage powertrain gives the ProStar ES downspeeding capability, allowing it to run 150-300 RPM slower at cruising speed vs. previous offerings.

The ES package also includes a choice of Dana Advantek 40 or Meritor's 14X high-efficiency 6x4 drive axles, or Meritor's FuelLite 6x2 drive axle, all riding on SmartWay certified tires.

"The ProStar ES delivers up to 11% better fuel economy as defined by our performance engineering team," Presswood says. "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." 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." he says.