Question: what is the most fuel efficient diesel truck?
Answer: The most fuel-efficient truck in the full-size segment is the Chevrolet Silverado 1500 Duramax, achieving 23/33/27 mpg city/highway/combined with RWD. The smooth 3.0-liter six-cylinder diesel engine makes 277 hp and 460 lb-ft of torque, and this output is routed through a quick-shifting 10-speed automatic transmission.