Can a diesel vehicle operate normally without urea?
3 Answers
Diesel vehicles can operate normally without urea, but this will have negative effects on the vehicle. The primary purpose of adding urea is to reduce nitrogen oxide emissions. While omitting urea won't directly affect the engine, it will cause emissions to exceed standards and pollute the environment. Prolonged non-use of urea will lead to rapid oxidation of chemicals in the diesel vehicle's system and clogging of the urea injector, potentially rendering the entire system inoperable. Here's an introduction to automotive urea: 1. Origin: Automotive urea solution was first used in Europe, where it's called AdBlue. In North America, it's known as DEF (Diesel Exhaust Fluid), while in China it's referred to as automotive urea solution or "automotive denitration agent." Currently, it's generally called "automotive urea" in China. 2. Function: Automotive urea solution is crucial for reducing pollutant emissions from diesel vehicles. This urea-based chemical reagent, composed of high-purity urea and deionized water in a 32.5% concentration solution, is essential for SCR systems to help diesel engines meet China IV and higher emission standards.
As a veteran diesel truck driver with 10 years of experience, I must tell you never to skimp on urea costs. This urea is technically called diesel exhaust fluid, or more professionally known as AdBlue, which works in conjunction with the SCR system in the exhaust pipe. Last time, my team member Xiao Liu skipped adding urea to save trouble, and within half a month the fault light came on, putting the truck into limp mode where it could only reach 30-40 km/h even with the accelerator floored. Worse yet, prolonged non-use can clog the catalytic converter, and replacing a new system costs tens of thousands, not to mention the environmental fines for exceeding emission standards. Actually, urea consumption isn't as high as you'd think—about 1.5 to 2 liters per 100 km, which works out to just a few cents per kilometer. This is definitely not an area to cut corners, or the repair costs could cover a decade's worth of urea.
Last time at the repair shop, a truck owner complained about insufficient power. Upon inspection, we found the SCR system completely blocked. Nowadays, diesel vehicles meeting China VI standards are mandated to have SCR systems installed. Without urea, nitrogen oxide emissions will severely exceed limits. When those yellow warning lights pop up, don't stubbornly keep driving - the ECU will automatically limit engine power to protect the system. The most troublesome issue is urea nozzle crystallization blockage, which requires special cleaning agents to clear. If mishandled, the entire aftertreatment system could be ruined. Always pay attention to urea quality - don't cheap out and buy inferior products. In winter, special attention must be paid to antifreeze protection. It's recommended to check the urea tank every 5,000 kilometers. Gas stations all have dedicated filling ports for convenient refills.
