Freightliner Cascadia is the industry leader for fuel economy (7–8 MPG) and parts availability.
The Volvo I-Shift is often cited as the smoothest automated manual on the market. ⚠️ Buying Red Flags what is the best used semi truck to buy
Look for trucks with 300,000–500,000 miles . This is typically after the steepest depreciation but before major engine overhauls (usually needed around 700k–900k miles). Freightliner Cascadia is the industry leader for fuel
Avoid trucks with recently deleted after-treatment systems (DPF/EGR) unless there is clear proof of trouble-free service. and International for its proven reliability.
The Detroit DD15 is highly regarded in Cascadias , while the Cummins X15 is a favorite across Peterbilt, Kenworth, and International for its proven reliability.