Which Vehicles Require Urea Solution?
3 Answers
All National IV standard diesel vehicles require the addition of urea solution. The reason for adding urea solution is that modern diesel engines have higher combustion efficiency and greater torque compared to older models, meaning they can haul more and run faster with the same amount of fuel. However, the high-temperature combustion process generates new nitrogen oxide emissions. The hazards of not using automotive urea include: 1. Damage to the vehicle's engine; 2. Damage to the SCR system; 3. Harm to the air. The function of automotive urea solution is to convert nitrogen oxides in vehicle exhaust into harmless nitrogen and water, achieving energy savings and environmental protection, thus helping vehicles meet national exhaust emission standards. Through the intelligent control of the SCR system, when the urea solution level in the storage tank is insufficient, the vehicle may fail to start. To ensure normal vehicle operation, an adequate supply of urea solution should be maintained.
I've noticed many diesel vehicle owners are confused about AdBlue. Simply put, almost all diesel vehicles meeting China IV emission standards or above require it. Especially heavy-duty vehicles like trucks and buses - those emitting white exhaust smoke on the road are typically using urea systems. Its technical name is Diesel Exhaust Fluid (DEF), primarily used to treat exhaust gases by breaking down nitrogen oxides into harmless water and nitrogen. Older diesel vehicles didn't need this, but with stricter environmental regulations now, engines will limit torque without AdBlue, making the vehicle undrivable. Long-haul truckers usually carry two barrels, refilling it regularly like fuel. From my experience, when the AdBlue warning light comes on, refill immediately - otherwise you risk getting speed-limited on the road.
Working in logistics these years, I deal with diesel vehicles every day, and urea solution has become a necessity. Whether it's National V or VI diesel light trucks, heavy trucks, or long-distance buses, none can do without it. The principle is that the exhaust after-treatment system uses urea to break down harmful gases. Once, a driver in our fleet forgot to add urea, and the vehicle's computer directly limited the engine power—speed couldn't go beyond 60 km/h no matter what. The filling port is usually near the fuel tank, easily recognizable by its blue cap. A reminder to all drivers: never use agricultural urea mixed with water as a substitute, as impurities can clog the nozzle. Also, remember to buy the low-temperature antifreeze type in winter, the -11°C one that won’t crystallize below freezing.
