Features may include:
Environmental Protection Agency (EPA) Final Tier 4 (FT4) compliant engines with maximum fluid efficiency
The U.S. EPA and Environment Canada requires all off-road diesel engines with 25 hp or more to meet stringent FT4 emissions regulations. John Deere uses the most efficient and cost effective solution for the tractor package to meet emissions requirements at each horsepower level. The 5M delivers a hassle-free emissions solution that allows faster work speeds and operation with ease.
The engine powering the 5E is EPA-certified Tier Level 4. This is achieved through a combination of a diesel oxidation catalyst (DOC) and a selective catalyst reduction (SCR) using diesel exhaust fluid (DEF, or urea).
Several defining features on the 5E maximize the performance and reliability of the emissions package. A completely shielded DOC/SCR not only protects essential components from damage but also keeps out dirt and debris. The well-packaged and tightly organized circulation system means there is more room to work around the tractor.
DOC
Deere has chosen to utilize an exhaust filter (DOC) to reduce particulate material so the engine can operate at a level which produces less NOx. With less NOx created, it requires less DEF to treat. The result is improved total fluid economy (diesel and DEF).
The engine is programmed to aggressively respond to changes in power needs, which can temporarily increase particulate matter. Since the exhaust filter removes particulate matter instead of the engine, the engine is left free to do what it is designed to do –—delivering all of the power, torque, plus transient response needed at the exact moment needed.
DEF
DEF is an ISO 22241 standard aqueous urea solution consisting of 32.5 percent urea and has a freezing point of -11 degrees Celsius (12 degrees Fahrenheit). A DEF tank keeps the customer in the field longer even when the temperatures drop below freezing. The DEF tank header is integrated with a temperature sensor and plumbed engine coolant lines are used to promote thawing and prevent freezing in the tank during operation.
SCR
To reduce the NOx, DEF, or urea, is injected into the exhaust stream. When the exhaust gases combine with the DEF in the SCR catalyst, the NOx is broken down into nitrogen and water vapor.
How EGR works
EGR reduces the high temperatures where these compounds are formed in the engine cylinders by replacing excess oxygen with a prescribed amount of cooled exhaust gas.
Exhaust gases contain more carbon dioxide than oxygen. The EGR valve, in conjunction with the venturi tube, and ECU, allow a controlled amount of exhaust gas to enter the intake manifold to mix with the incoming fresh air.
Replacing excess oxygen with cooled exhaust gas leads to:
In addition, EGR allows for:
For added performance and efficiency, the engine passes the exhaust gases through an EGR cooler before it enters the engine.
Exhaust airflow enters into the EGR cooler from the exhaust manifold near the turbocharger. Based on engine load, air temperatures, and rpm, the engine control unit (ECU) opens or closes the EGR valve, allowing a measured percentage of exhaust gas to enter the intake manifold. The gases mix with the rest of the incoming air from the turbocharger and aftercooler before entering the cylinders.