Shelf Life of Diesel Exhaust Fluid DEF (2024)

FAQs

Shelf Life of Diesel Exhaust Fluid DEF? ›

It will degrade over time, but if stored at temps between 10 degrees and 90 degrees, DEF has an expected shelf life of one year. You can extend the shelf life to two years by storing at a temperature that stays around 75 degrees. If you see a color change, the fluid is likely compromised.

That reservoir's fill cap is under the hood atop the left fender. According to the owner's manual, a full DEF tank should last 6300 miles, but, as everyone knows by now, your mileage will vary.

Store DEF out of direct sunlight. If DEF is stored outside it must be shaded from the sun. SHELF LIFE SHOWN IN THE BELOW CHART, IF AVERAGE DAILY TEMPERATURES WILL CONTINUALLY EXCEED THOSE SHOWN IN THE CHART BELOW. UNDER NO CIRc*msTANCES SHOULD DEF BE KEPT FOR MORE THAN 3 YEARS.

If you store DEF outside, it must be kept out of direct sunlight and stay under shade. If it is kept in direct sunlight for any sustained period of time, it begins to lose its urea potency. DEF must be stored below 86°F or in the coolest area of your storage facility.

DEF should be stored at a temperature range between 15 degrees Fahrenheit and 77 degrees Fahrenheit. DEF can withstand freezing without any performance impact, but it's especially sensitive to heat. DEF freezes at 12 degrees Fahrenheit and can be restored through thawing.

Typically, DEF expiration dates are set at one year from the date of manufacture. The shelf life of DEF comes from its makeup. DEF is simply water and urea, with a 32.5% urea concentration. This solution of synthetic urea and deionized water binds with and helps neutralize harmful emissions in diesel exhaust.

Because it doesn't include any preservatives, DEF does come with a shelf life. The good news is, it's a fairly long shelf life; DEF can usually be stored up to one year without any issues.

Potential equipment malfunctions and issues, such as unexpected engine shutdowns. Damage to vital vehicle and equipment components such as the diesel particulate filter and the DEF dosing pump. Malfunction or damage to a vehicle's Selective Catalytic Reduction (SCR) system.

The date you see is the packaging/filling date (batch code). Stored properly should last 1-2 years from that date. If it's bad, you will know by the color of it, since new def looks clear like water.

The shelf life of DEF is directly related to the temperature at which it is stored. Storage temperature between 12º and 86º F are recommended to maintain optimal shelf life of up to two years. If BlueDEF freezes, its efficacy will not be effected upon thawing.

How do you winterize a DEF fluid? ›

Shelf life of DEF. Shelf life depends on the temperature of your storage facility. According to ISO22241 standards, ideal storage temperatures for DEF should be between 12°F and 86°F. When stored at lower temperatures, shelf life is extended.

DEF is made mostly of water, with the other part being urea. That means that DEF will freeze if it's stored somewhere that's exposed to freezing temperatures.

The freezing point of DEF is 12 degrees Fahrenheit and -11 degrees Celsius. If you're driving in low temperatures, it's important to leave some room in the DEF tank. If the DEF tank is completely full, when it freezes, the water in it will expand and could crack the tank.

If the DEF tank contains less than 5% of its capacity, the equipment engine power will de-rate. Enough power will be available, however, to travel a short distance, so that you can add more fluid to the tank. The DEF tank needs to be filled once for every 3 to 4 times that you refuel with diesel fuel.

Typically, dose rates for a well-maintained heavy- or medium-duty truck engine will be between 2-3%. This means that a truck getting six mpg will require between three to five gallons of DEF for every 1,000 miles it travels.

How Often Do You Have to Add Diesel Exhaust Fluid? 2.5 gallons of DEF will last approximately 800 miles on the road. That means, 1 gallon of DEF will last about 300 to 500 miles. You can figure, for every 50 gallons of diesel, you'll need 1 gallon of DEF.

To tell if your DEF has gone bad, you can often look at the fuel itself. When DEF is in good shape, the liquid should look clear – free of any contaminants or discoloration. If you find that your DEF is colored, cloudy, or hard to see through, you will want to replace your DEF immediately to avoid issues.