The Precedent S-Series features a >25 horsepower engine with emission control technologies that minimize fuel consumption and deliver lifelong emissions compliance.
Developed to achieve emissions compliance, the Precedent engine is notable for what it does not have: a Diesel Particulate Filter (DPF). Because of the way a transport refrigeration unit (TRU) runs, with its frequent stops/starts, light engine loads and low exhaust temperatures, using a DPF to achieve compliance is problematic. When we also considered the negative impact on engine life and fuel efficiency that a DPF brings, it was clear that a DPF had no place in the Precedent platform.
To control emissions, we chose proven technologies that are ideally suited to TRU operation. The high pressure common rail fuel delivery system controls particulate matter within the cylinder while improving efficiency and performance.
Our “EGR Light” system recirculates a small amount of exhaust back into the combustion chamber in certain load conditions to help control NOX emissions. A unique “fail closed” design assures continued peak engine performance if a failure occurs, ensuring load integrity is maintained. Additionally, the Diesel Oxidation Catalyst (DOC) provides maintenance-free performance for the life of the unit.