This Semi Truck’s 10 MPG Might Sound Terrible, But Here’s Why That’s Incredibly Efficient

The fifth-generation Freightliner Cascadia, launched in 2024, is capable of up to 10 MPG while hauling over 40,000 pounds in payload. This is a significant improvement over other semi trucks, with most struggling to return 7 MPG.

Freightliner achieved this efficiency through hundreds of small changes, including aerodynamic shaping, such as a deep flexible front air dam and a ‘Max Aero Bumper’ that pushes air out through the front wheel wells.

The truck is also equipped with a Detroit DD15 Gen 6 engine, a 14.8-liter inline-6 engine delivering up to 1,850 pound-feet of torque.

The company has seen a cumulative 35% improvement in economy over the last 12 years, with the current generation seeing a 1.9% improvement over the previous model.

The aerodynamic tweaks also contribute to a 50% reduction in cab noise, reducing stress and fatigue for the driver and improving road safety.

While other trucks, such as those from Kenworth, Volvo, and Peterbilt, are catching up, the Freightliner Cascadia remains one of the most efficient diesel tractors on the market.