What are the main components of automotive urea?
2 Answers
Automotive urea is primarily composed of 32.5% high-purity urea and 67.5% ultrapure water (deionized water). It is colorless, translucent, non-toxic, but corrosive. Specific details are as follows. Storage of automotive urea: When storing automotive urea, exposure to sunlight should be avoided. However, prolonged temperatures below 25°C can cause urea to decompose or water to cool, leading to deterioration of the automotive urea solution. Therefore, the storage environment should be kept at no less than 25°C and stored away from light. Additionally, when the urea solution freezes, its volume decreases by about 7% compared to its liquid state, so sufficient storage space should be reserved when storing at low temperatures. Timely addition of urea: There is a dedicated urea tank in the vehicle where urea is added. As long as the vehicle is running, urea will be consumed, so it should be replenished promptly. Generally, about 4 liters of urea are consumed per 100 liters of diesel. The exact consumption depends on factors such as engine displacement, model, manufacturer, etc. Different road conditions and loads will also affect urea consumption.
The main component of automotive urea is essentially a solution made from high-purity urea and ultra-pure water, commonly referred to as urea water or automotive urea fluid by regular vehicle owners like us. I've been driving diesel vehicles for over a decade, from National IV to National VI models, and have been using this throughout. The concentration is typically around 32.5%—too concentrated or too diluted won't work, otherwise the post-treatment system will trigger fault codes. Initially, I was quite puzzled about why this was necessary, but later understood that without it, the exhaust treatment system would limit the vehicle's speed, making it feel like it's being choked. Nowadays, I always check the urea fluid level whenever I refuel, especially before long trips. I recommend buying reputable brands, as products from small workshops tend to crystallize and clog the nozzles, and a single repair could cost half a year's supply. Storage is also important—leaving it in the trunk during summer can cause it to deteriorate, and in winter, it's best to use an anti-freeze type.
