All About the International LT Exterior: Part 1

January 21, 2021

Uncle Al's Tech Tips of the Week

The information in this tech tip is to educate UTC staff and ensure customer satisfaction and safety.

How Does the International LT Exterior Reduce Drag?

Vehicles rarely drive perfectly into the wind, so there is nearly always some amount of crosswind or yaw. The International LT exterior was designed to deliver the lowest possible amount of aerodynamic drag across all conditions by minimizing the wind average drag coefficient. You’ll notice all the surfaces of the LT Series are rounded, which is a key technique for reducing drag in crosswinds. In short, rival models with straighter and more squared edges are less optimized for driving in crosswinds.

Advanced Trailer Aerodynamics

Every inch of the International LT is designed to cut smoothly through crosswinds. Here are just a few examples:

  • Looking at the hood, you’ll notice more crown—meaning that the middle in front of the windshield is higher, and quickly tapers to the sides and front.
  • The bumper to back-of-cab (BBC) dimension was increased from 122 to 125 inches, which further improved aerodynamics.
  • Wheel openings were sculpted to move air around the wheels.
  • The new 3-piece bumper includes a valance which comes in two versions, depending on whether the truck predominantly hauls skirted or not skirted trailers. Wind tunnel testing showed that the overall tractor-trailer aerodynamics depended on the relationship between the valence and the presence of trailer skirts. The bumper is also entirely composite and does not require a steel brace behind it, which reduced weight, eliminated corrosion, and increased foot space for mechanics to service the vehicle.
  • All new two-piece skirts include a flare-out at the end to guide air around the rear wheels, without the need for a third skirt piece. This eliminated the extra cost and weight associated with a three-piece skirt design. The skirts can be removed with four bolts for easy access and include a piano style hinge battery access panel. Simply lift to perform daily DOT inspections and magnets retain it closed. The skirt strips have reduced ground clearance to keep air out from beneath the vehicle. To prevent damage, the new strips are very flexible and include a round-bottom profile to encourage the strips to bend when cresting railroad tracks, for example. (Kick or push the skirt strip in a couple inches as a demonstration of flexibility). The leading edge is also at a 45-degree angle to prevent damage. As the vehicle moves through the air, the hood and windshield push air to the sides and above the vehicle, at nearly double the vehicle speed.
  • The new pedestal mirrors were placed forward, in a region of lower air speed, to greatly reduce their drag. They deliver 0.5% better fuel economy than their c-loop mirror counterparts.
  • The new 22-inch cab extenders are 4 inches longer than ProStar® and reduce the tractor to trailer gap. Every 6-inch reduction improves fuel economy by approximately 0.5%. Finally, the International LT exterior uses a hard plastic at the trailing edge. This retains its shape over the life of the vehicle to maximize aerodynamics. Competitive vehicles using softer materials appear wavy over time and deliver reduced aerodynamic benefits in the long run.

Browse Our International Truck LT Models for Sale

All that technology—along with the 2017 Greenhouse Gas-compliant engines—help LT Series trucks to deliver up to 7% better fuel economy than today’s ProStar®! Interested in a used International LT for sale? Explore our inventory online and stop by an International Used Truck location near you to learn more about the LT exterior or interior features today.

Alan Hertzog

UTO Training Manager

Navistar Inc.-WHQ

2701 Navistar Drive.

Lisle , IL 60532

And More

International Used Truck Center 41.776180, -88.200918.