10 Diesel Engines Packing the Most Horsepower You’ll Actually Care About

1. Mercedes-Benz OM 656 I6 Turbo Diesel — Tech Meets Power

Mercedes cranks out this 2.9-liter inline six with two trims: the 350 d at 286 HP and the beefier 400 d at 340 HP and 516 lb-ft torque. It’s their strongest diesel, loaded with high-tech turbocharging and fancy valve controls to save fuel and keep emissions low — about 46 MPG. You’ll find it powering various Mercedes SUVs and sedans since 2017.