"National Ⅳ emission standards in promoting the implementation process, nothing more than the most discussed three issues: price, fuel quality and supply of urea in the early country Ⅳ conduct, we will focus on the exploration and study are due to product prices. the purchase and consumption leads to disruption of response measures and methods, but in the process of implementation of the country Ⅳ found that the problem is not so outstanding price performance, but is low-sulfur oil supply and urea supply and quality as the implementation of the country Ⅳ 'catching '. "Hangzhou car urea manufacturers association said, speaking from a professional point of view, although the use of high-sulfur fuel oil might generate sulfate, and the attachment surface of the catalyst after the treatment, resulting in the conversion efficiency decreased emissions of nitrogen oxides exceeded, OBD alarm triggered. However, the surface of the catalyst adhered sulfate is reversible, filling low sulfur fuel in the vehicle or a high-load operating conditions of work for some time, adhered to the surface of the catalyst will automatically sulfate thermal decomposition, and therefore the vehicle will not "paralysis", "lying nest" and other issues. From the car with urea property point of view, from the factory to the effective use of the term, there are strict requirements, coupled with the product for manufacturing, packaging storage, transmission and distribution system requirements, the use of procedures such as filling systems have very strict requirements. Unfortunately, due to the implementation of the national emission standards Ⅳ postponed again and again, the car industry with a capital investment of urea is not guaranteed, it leads to active participation and input from industry, to negative watch and wait. "WEI force said:" With this country Ⅳ standard gradually implemented in the country, the number of vehicles in the country Ⅳ increasing in 2015, is expected to State Ⅳ vehicle also will be doubled, and the market demand for urea will shoot up then urea system construction, filling, quality problems have to be solved as soon as possible. Industry trade associations to provide early warning for the urea market, otherwise the vehicle may occur with urea market blowout blind investment. Under this background, China Internal Combustion Engine Industry Association of urea production companies and diesel engine manufacturing enterprises, reference to the prevailing approach to Europe, jointly drafted the "management approach" and the "rules." "Car Urea: content 31.8-33.2% chloride, ㎎ / kg ≤0.2 density, ﹝ 20 ℃) ??g / ml 1.087-1.092 aldehydes, ㎎ / kg ≤5 refractive index, ﹝ 20 ℃) ??1.3814-1.3843 potassium, sodium, calcium, magnesium, iron, aluminum, ㎎ / kg ≤0.5 biuret,% ≤0.3 zinc, nickel, chromium, copper, ㎎ / kg ≤0.2 alkalinity (NH3 dollars),% ≤0.2 not matter , ㎎ / kg ≤20 phosphate, ㎎ / kg ≤0.5 crystallization temperature of -11.0 ℃