What is the Function of Diesel Exhaust Fluid?

3 Answers
DelAddyson
07/28/25 9:15pm
Diesel Exhaust Fluid (DEF) serves purposes such as exhaust purification and cost reduction. Specific details about DEF are as follows: 1. Exhaust Purification: It reacts with nitrogen oxides in the exhaust, reducing nitrogen oxide emissions. 2. Cost Reduction: It can be used to optimize engine performance and fuel consumption, reducing diesel consumption by up to 6%, significantly lowering costs. 3. DEF is an essential additive for SCR (Selective Catalytic Reduction) systems. The SCR system operates as follows: when nitrogen oxides are detected in the exhaust pipe, the DEF tank automatically sprays diesel exhaust fluid, which then reacts with nitrogen oxides in the SCR catalytic reaction tank through redox reactions, producing non-polluting nitrogen and water vapor that are expelled.
Was this review help?
14
4
Share
EstherDella
08/12/25 12:52am
I've always driven diesel vehicles, and the primary function of AdBlue (diesel exhaust fluid) is to help treat harmful substances in the exhaust, making the vehicle more environmentally friendly and compliant. If you don't use it, emissions will exceed standards, potentially resulting in fines and contributing to air pollution. From my personal experience, using AdBlue effectively reduces nitrogen oxides (NOx), which are major contributors to poor air quality, especially during severe summer haze. When driving long distances, toll stations often check emission data—having sufficient AdBlue ensures a smooth pass, saving a lot of hassle. Additionally, it doesn’t harm the vehicle itself; instead, it protects the SCR system and extends its lifespan. The only catch is the need for regular top-ups—check the fluid level every few thousand kilometers and refill it for peace of mind. Remember, don’t wait until the warning light comes on to refill, or you might face trouble on the road.
Was this review help?
2
2
Share
Expand All
OBraxton
09/30/25 8:42am
I think diesel exhaust fluid (DEF) is truly amazing. It significantly reduces exhaust pollution and makes a considerable contribution to the environment. Through my participation in community environmental activities, I learned that nitrogen oxides emitted by diesel vehicles have a major impact on health. After adding DEF, they are converted into harmless nitrogen and water vapor, reducing sources of air pollution. In the long run, this is very helpful for urban haze control, and we are all working to leave a greener world for the next generation. When driving my own car, I make it a habit to add AdBlue on time to keep the SCR system working efficiently. This makes driving more reassuring and prevents engine performance degradation due to emission issues. Simply put, it's a small investment—just buying a little eco-friendly tool that lasts quite a while with each refill.
Was this review help?
14
2
Share
Expand All
More Forum Discussions

How to Start the Mazda 3 When the Remote Battery is Dead?

To start the Mazda 3 when the remote battery is dead, place the remote in the designated key fob recognition area, then press the start button to ignite the engine. Functions of the key include: 1. Automatically closing windows after turning off the engine; 2. Facilitating car location in parking lots; 3. Automatically opening the trunk; 4. Remote-controlled window operation. The Mazda 3 features a MacPherson strut front suspension and a torsion beam rear suspension. It is equipped with a 1.5L naturally aspirated engine delivering a maximum horsepower of 117 PS, a peak power of 86 kW, and a maximum torque of 148 Nm, paired with a 6-speed manual transmission.
19
2
Share

Should a new turbocharged car use 5w30 or 40?

Both 5w30 and 40 are suitable for new turbocharged cars. Turbocharged engines operate under high temperatures and pressures, requiring higher viscosity engine oil to provide adequate lubrication. Effects of low oil viscosity: During normal engine operation, oil forms a protective film on engine components to reduce wear. If the oil viscosity is too low, it cannot form a stable protective film, which accelerates engine wear. Advantages of turbocharged engines: When properly matched and operating under positive boost pressure, they can reduce emissions and exhaust noise while significantly increasing power output with minimal size increase. Disadvantages include slower acceleration response and less linear/smooth operation.
2
4
Share

Which Subject is Hill Start in the Driving Test?

Hill start is part of Subject 2 in the driving test. Precautions for hill start: Pay attention to the situation in the rearview mirror. The distance between the car body and the sideline should be kept at about 30 centimeters. When you observe through the rearview mirror that the lower part of the mirror overlaps with the control line, press the clutch and brake, and be careful to prevent the car from rolling backward. Precautions for starting on a slope: After completing the hill start, remember to turn on the left turn signal, slowly release the clutch, and when you feel the car's front shaking or the engine sound becoming muffled, slowly release the brake to prepare for starting.
9
1
Share

Where is the fuse for the BMW 530 compressor located?

Under the yellow clip cover on the passenger side. Automotive compressor: The automotive compressor is the core component of a car's air conditioning system. It is responsible for drawing in low-pressure gaseous refrigerant, compressing it into high-pressure gaseous refrigerant, and discharging it, thereby providing the driving force for the refrigerant's circulation. Working principle of the compressor: The compressor in a car's air conditioning system is directly driven by the engine through a belt drive mechanism. When the compressor is not in operation, it can be disengaged from the engine via an electromagnetic clutch. When the air conditioning system is not in use, regularly check the belt tension to ensure the clutch operates correctly. Sometimes, bearing damage in the clutch can affect the compressor's shaft seal, leading to refrigerant leakage at the shaft seal.
4
0
Share

How to Deal with High Fuel Consumption in Nissan Cefiro A33?

There are three main reasons for the high fuel consumption in Nissan Cefiro A33. The first reason could be carbon deposits in the engine, leading to insufficient power, delayed gear shifting, and increased fuel consumption. This is a relatively common issue, and the solution is to clean the carbon deposits in the intake, exhaust, and combustion systems. A simple cleaning can restore the car's fuel consumption to normal. The second reason is that the fuel supply learning value is too high. This is easy to handle—just disconnect the negative terminal of the battery for 30 seconds and then reconnect it. However, ensure that other learning values are not lost, as this could complicate the issue. The final reason is whether there is any dragging in the walking system or brake system. If this fault occurs, the solution is straightforward—take the car to a repair shop or a 4S store for maintenance.
8
0
Share

Is the Big Green Book the Vehicle License?

The Big Green Book is not the vehicle license. Meaning of the Big Green Book: The Big Green Book is the motor vehicle registration certificate. The motor vehicle registration certificate is the property certificate of the motor vehicle, a legally recognized document, kept by the owner of the motor vehicle and not carried with the vehicle. If the motor vehicle registration certificate is lost, it needs to be reissued promptly. Meaning of the Vehicle License: The motor vehicle license is the legal document that permits the motor vehicle to drive on the roads within China. The vehicle license consists of three parts: the license holder, the main page, and the supplementary page. The front of the main page is the signed certificate core, and the back is the photo of the motor vehicle, sealed in a plastic cover. The supplementary page is the signed certificate core.
16
1
Share
Cookie
Cookie Settings
© 2025 Servanan International Pte. Ltd.