What is the urea added in cars?
3 Answers
Urea added in cars is a liquid used in SCR technology to reduce nitrogen oxide pollution in diesel vehicle exhaust. Its composition consists of 32.5% high-purity urea and 67.5% deionized water. Automotive urea needs to be replenished approximately every 2,000 kilometers, with 3 to 5 liters of urea used per 100 liters of diesel fuel, which equates to 3% to 5% of the fuel consumption. The reason for adding urea to cars is that the harmful substances in diesel vehicle exhaust are mainly nitrogen oxides and particulate matter. While particulate emissions can be reduced through technical means inside the engine, the exhaust primarily contains nitrogen oxides. By injecting urea into the exhaust after-treatment device, the urea decomposes into ammonia at high temperatures, which then reacts with nitrogen oxides in the presence of a catalyst to produce harmless nitrogen and water.
As an automotive technology enthusiast, I understand that the urea added to cars is specifically designed for the SCR system in diesel vehicles as an exhaust treatment fluid. Its main components are high-purity urea and an aqueous solution, typically a mixture of 32.5% urea and deionized water. The SCR system injects urea into the exhaust pipe, where it decomposes into ammonia to neutralize harmful nitrogen oxides, producing harmless nitrogen and water vapor, thereby significantly reducing vehicle emissions. This stuff is crucial for environmental protection and complies with global emission standards. If not replenished in time, the dashboard will issue a warning, and the engine may enter a speed-limiting mode, affecting performance. I often remind people to use reputable brands like AdBlue to avoid clogging the system with impure liquids. Urea may freeze at low temperatures, but modern vehicles come with built-in heaters. Regular top-ups are cost-effective, costing just a few dozen yuan per barrel, not only protecting engine components but also contributing to urban air quality.
I drive a diesel pickup truck, and adding urea has become a daily routine. This liquid is key to solving exhaust pollution, neutralizing harmful gases under the SCR system. It's usually checked every 5,000 kilometers, and there's a dedicated filling port at gas stations—I simply pour it into the small tank using a funnel. The cost is low, about 100 yuan per barrel, and it's convenient to use. If you don't add it, the vehicle will light up a warning and even reduce power. Once, I neglected it, and the sudden speed limit on the highway gave me a scare. The benefits are clear: it reduces black smoke emissions, making driving cleaner, and complies with regulations to avoid fines. I think this small investment is worth it—simple maintenance and eco-friendly. When storing urea, avoid direct sunlight and choose certified products to ensure the system's longevity.
