During the launch of the new Cummins 6.7-liter turbo diesel engine, I sat down with Doug Killian, Stellantis Chief Vehicle Synthesis Manager, to walk through the engineering changes. While the new engine features improvements to fuel delivery, serviceability and refinement, one question quickly surfaced from viewers after I published my first video: Why did Cummins continue using hydraulic lifters instead of returning to flat tappets? Why Cummins Chose Hydraulic Lifters Instead of Flat Tappets The question about hydraulic lifters isn’t new. Diesel owners have watched hydraulic lifter failures become a hot topic in some gasoline engines, leading many to wonder whether […] (read full article...)