Which Vehicles Require Urea?
2 Answers
Vehicles that require urea include: heavy-duty trucks, buses and other diesel vehicles. Automotive urea refers to diesel exhaust fluid (DEF), primarily used in SCR technology to reduce nitrogen oxide emissions from diesel exhaust. To meet annual emission inspection standards, diesel vehicles must be equipped with an SCR system for exhaust treatment. Automotive urea is used by the SCR system to process nitrogen oxides in exhaust gases. DEF is an essential additive for SCR systems. When nitrogen oxides are detected in the exhaust pipe, the urea tank automatically sprays DEF, which undergoes redox reactions with nitrogen oxides in the SCR catalytic converter, producing harmless nitrogen gas and water vapor for emission.
After driving for so many years, I know that vehicles that primarily require urea are diesel-powered ones, especially heavy-duty trucks and buses. During long-distance transportation, I often see drivers refilling AdBlue urea solution to reduce nitrogen oxide pollution from the exhaust pipes. This is because modern emission standards are becoming increasingly stringent, such as under regulations in Europe, the U.S., and China, diesel vehicles must be equipped with SCR systems to meet the standards. Without it, the vehicle may be speed-limited or unable to run, which is quite troublesome. I’ve driven some diesel SUVs myself, like the Volkswagen Tiguan or the Mercedes-Benz GLK diesel versions, which also use urea to maintain environmental compliance, but a single refill can last thousands of kilometers and isn’t expensive—service stations can handle it. Overall, both commercial vehicles and some passenger cars rely on it.
