L5P Duramax 2017-2021

L5P Duramax Performance Parts & Upgrades

Exterior Accessories

This L5P Duramax is the next-generation redesign offers more horsepower and torque than ever. Higher boost pressure from the turbocharger, compared to the previous engine, helps the L5P produce more power.

Along with a 19 percent increase in max torque over the current Duramax 6.6L, the redesigned turbo-diesel’s performance is quieter and smoother, for greater refinement. In fact, engine noise at idle is reduced 38 percent.

The 6.6L Duramax L5P is an entirely new powerplant. The development of this fifth-generation V-8 is more of a rebirth than an evolution. Every single part, down to the nuts and bolts, is reengineered to be stronger. The only thing it shares with its predecessors is the size of the bore and stroke. GM took all the knowledge gained from the older generations (weak links, trouble spots, design flaws, and so on) and made improvements to make the L5P stronger and more powerful than its forebears. The newest eight-cylinder Duramax produces 445 hp and 910 lb-ft of torque in stock trim, annihilating the 397hp/765–lb-ft performance of the LML engine it replaces.