The primary differences between the 2017 L5P and the 2020 L5P Duramax engines are found in their emissions systems and power ratings. The 2020 model received an updated emissions system, which meets stricter environmental standards. Additionally, the 2020 L5P has a slightly higher power rating, producing 445 HP and 910 lb-ft of torque, compared to the 2017 model's 445 HP and 910 lb-ft of torque.