The Formula of Vehicle Urea and How to Mix It
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Formula for vehicle urea solution: 1. Urea: White or light yellow, needle-like or prismatic crystals, with little or no powder. High-quality urea: (1) Appearance: Uniform crystals with consistent hardness. (2) Color and shape: White or light yellow prismatic crystals without impurities. (3) Gloss and texture: Translucent crystals with no surface reflection, smooth, loose, and not damp to the touch. (4) Burning test: Melts, emits white smoke, and has an ammonia odor. 2. Mixing ratios: (1) Standard urea solution: High-purity urea 32.5%, deionized water 67.5%. (2) Antifreeze urea solution: High-purity urea 32.5%, deionized water 52.5%, methanol 15%.
I recently studied the formula and ratio of diesel exhaust fluid (DEF), which mainly consists of mixing high-purity urea with deionized water. The standard ratio is 32.5% urea to 67.5% water. Why this specific ratio? Because if it's too low, the urea won't dissolve properly, and if it's too high, it can crystallize and clog the SCR system in diesel vehicles. From my interactions with some drivers, I’ve learned that using tap water or incorrect ratios can introduce impurities that damage the injector nozzles, costing hundreds or even thousands to repair. The pre-mixed DEF available on the market already has the correct ratio, so it’s best to avoid mixing it yourself and opt for reputable brands like AdBlue for convenience. Also, when refilling DEF, always pay attention to the vehicle’s warning lights—don’t push it until the tank is empty, as this can lead to emission violations, fines, and environmental harm. Store the fluid in a cool, dry place, away from children’s reach, as safety is paramount.
