Since the car is a consumable with urea, after consuming finished, the owner subject to price or convenience considerations, the car will stop adding urea. According to reports, the use of SCR technology routes country Ⅳ diesel engines, if there is no urea solution on the NOx in the exhaust gas catalytic reduction, then the engine emissions not only from country Ⅳ, not even as the country Ⅱ, but will result in more serious pollution. To solve this problem, the government both in Europe and in addition to reward and punishment policy outside, have asked to install a vehicle OBD system that monitors the content of the urea solution, when below a certain level, the car engine will not be start until you have added urea so far. Limited the impact of technology and marketing, the car will not appear in large numbers in the state of production of urea First, technical barriers increase the cost. Information from the public point of view, Europe Yara is completely gas-based urea to synthesize urea car, its technology is already quite mature. Meanwhile, its domestic joint venture with Sinochem Fertilizer companies also claimed that the future of all raw materials will be sourced from gas-based urea. Overall, since the coal-urea production process, contain more dust or the like, and finally the control of impurities as compared to the raw material gas to clean a disadvantage. While the final purification can also be obtained by qualified products, but tons of consumption and disposal costs will rise, so gas-based urea will have an advantage in terms of cost. And those processed through market purchases of urea, compared with urea even no cost advantage. Secondly, the channel more difficult to go beyond the barriers. Learn from the experience overseas and domestic marketing was still a most convenient use of existing gas station. By comparison, after the European automotive retail price of urea, have come to the business from production to sales in the middle part of the cost of huge conclusions. Therefore, the future of domestic promotion, no channel advantages of business if it were self-built filling station or retail, the cost will drastically increase. Currently existing domestic enterprises, which are mostly marketing cooperation with the local bus companies and other large customers. However, this approach is difficult to penetrate the numerous individual drivers of passenger cargo.