What is the consumption ratio of automotive urea to fuel?
3 Answers
The consumption ratio of automotive urea to fuel is 100:5. Introduction to automotive urea: Automotive urea is used in diesel engines. It is a liquid applied in SCR (Selective Catalytic Reduction) technology to reduce nitrogen oxide pollution in diesel vehicle exhaust. Its composition consists of 32.5% high-purity urea and 67.5% deionized water. Function of automotive urea: The main harmful substances in diesel vehicle exhaust are nitrogen oxides and particulates. Particulate emissions can be reduced through technical means inside the engine, leaving mainly nitrogen oxides in the exhaust. By injecting urea into the exhaust after-treatment device, the urea decomposes into ammonia at high temperatures, which reacts with nitrogen oxides under the action of a catalyst to produce harmless nitrogen and water.
I've driven diesel vehicles for many years, often on long-distance trips. Based on my personal experience, the consumption of diesel exhaust fluid (AdBlue) is generally 3% to 7% of the fuel consumption. For example, when driving on highways, for every 100 liters of diesel burned, I need to add approximately 3 to 7 liters of AdBlue. This ratio can vary quite a bit—steep mountain roads increase AdBlue usage, while slow traffic in congestion saves some. My vehicle has a dashboard display for AdBlue levels, and I always check it before refueling to avoid alarms midway. If the AdBlue tank runs empty, the vehicle will limit speed, which is quite annoying, so I top it up every 1,000 to 2,000 kilometers—it's readily available at gas stations. If the ratio is unusually high, say above 7%, it might indicate a clogged injector or system malfunction, requiring immediate inspection and maintenance. Driving habits also affect this ratio; aggressive acceleration tends to consume more AdBlue, so smooth driving saves fuel and protects the vehicle.
Working at the auto shop, I've handled many diesel vehicle urea system repairs. The consumption ratio is typically set at 3% to 7% of fuel usage. This is determined by the matching design between the engine and SCR system. Urea is used to break down nitrogen oxides in exhaust gases - for every tank of fuel burned, a small portion of urea is consumed from the tank. For example, a heavy truck using 20 liters of fuel per 100 kilometers would consume approximately 0.6 to 1.4 liters of urea. The ratio fluctuates due to road conditions or aging factors - new vehicles have lower ratios, while older vehicles with sensor issues may exceed 8%. A common mistake is using cheap urea, which corrodes pipes and actually increases the consumption ratio. I advise drivers to regularly check nozzle conditions during maintenance, rather than waiting for warning alerts. Maintaining the correct ratio isn't just a regulatory requirement - it also extends exhaust system lifespan and reduces repair costs.
