What is the formula for automotive urea?

[DelFinn]

Automotive urea formula is: composed of 32.5% high-purity urea and 67.5% ultra-pure 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. The usage amount of urea is equivalent to 3% to 5% of the fuel consumption. The reason for adding automotive urea is: the harmful substances in diesel vehicle exhaust are mainly nitrogen oxides and particulates. 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.

[McAnderson]

Automotive urea is essentially a specialized liquid additive for diesel vehicles, designed to reduce exhaust emissions. Its formulation is remarkably simple: dissolving high-purity urea in deionized water, typically in a ratio of 32.5% urea to 67.5% water. You must use high-purity urea—lower grades contain impurities that can clog the vehicle's SCR system, which is notoriously sensitive and costly to repair when blocked. The water must also be deionized, as regular tap water contains minerals that risk crystallization and corrosion. As a truck driver with years of experience, I always meticulously select reputable urea brands—never opt for cheap knockoffs, or you’ll face frustrating warning lights during long hauls. When refilling, pour gradually to ensure system efficiency. This practice not only cuts nitrogen oxide emissions for environmental protection but also extends engine life, saving on repair costs. Most brands on the market share similar formulations, with purified urea and water as core ingredients, occasionally supplemented with stabilizers or antifreeze additives.

[McKendra]

The formula for automotive urea is quite standardized, with the core being 32.5% pure urea and 67.5% deionized water. This ratio isn't arbitrarily set—it's designed to generate just enough ammonia in the engine exhaust pipe to neutralize harmful gases like NOx. As someone who pays attention to environmental technology, I find this design quite clever. The urea must be of high purity, above 95%, and the water must be deionized to prevent corrosion of components. If impurities are introduced, the SCR catalyst can be destroyed, ironically increasing pollution. When using it, ambient temperature matters—in very cold conditions, you should opt for formulations with antifreeze additives to prevent freezing and pipe blockages, which would be worse. Nowadays, many vehicles come with urea tanks pre-installed, and one fill can last thousands of kilometers, though it's quite expensive. I always advise friends to prioritize products from major manufacturers—don't cut corners to save money and end up damaging your vehicle.

[Archer]

Automotive urea is primarily composed of pure urea and deionized water in a ratio of 32.5% to 67.5%. The urea must be of high purity, and the water must be treated to remove ions to prevent clogging the SCR system. As a diesel vehicle mechanic, I often encounter cases where owners use low-quality products indiscriminately, causing the malfunction indicator light to turn on. When adding it, the amount should be moderate—not excessive—just one bottle at a time is sufficient.