Mishimoto 13-18 Ram 6.7L Cummins Degas Tank - BlackIt's been a decade since the 2013 2018 RAM 6. 7L Cummins began to roll off the assembly line. While robust and reliable, the 2013 2018 RAM 6. 7L Cummins is only partially immune to the test of time. Stock components, like the plastic degas tank, become brittle and cloudy over time, making it prone to leaks and impossible to see the coolant level. The Mishimoto 2013 2018 RAM 6. 7L Cummins aluminum degas tank is the most effective way to ensure your