AdBlue & DPF
Using AdBlue
Does AdBlue go off?
CheckFuelPrices Editorial
Expert Written • 4 industry sources
Yes, AdBlue does go off. It has a shelf life of roughly 12–18 months when stored correctly, after which the urea content degrades and it becomes less effective at reducing harmful NOx emissions from your exhaust.
What AdBlue Is and Why It Degrades
A urea and water solution:
AdBlue is a precisely mixed solution of 32.5% urea and 67.5% deionised water. Over time the urea breaks down, reducing the solution's ability to neutralise nitrogen oxide emissions.
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Heat speeds up degradation:
High temperatures accelerate the chemical breakdown. Storing AdBlue above 25°C significantly shortens its usable life below the 12–18 month guideline.
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It can also freeze:
AdBlue freezes at around -11°C. Modern vehicles have a heated AdBlue tank to handle this, but containers stored outside in winter can freeze and crack.
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How to Store AdBlue Correctly
Keep it cool and dark:
Store AdBlue in a cool, shaded location away from direct sunlight. Between 10°C and 25°C is the ideal temperature range to preserve shelf life.
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Use sealed, original containers:
AdBlue is corrosive to metals such as copper and zinc. Always keep it in its original sealed container and avoid using metal funnels or jugs.
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Avoid contamination:
Even a small amount of contamination — including tap water, dirt, or the wrong funnel — can render AdBlue unusable and potentially damage your SCR system.
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What Happens If You Use Degraded AdBlue
Reduced emissions performance:
Degraded AdBlue cannot properly convert NOx gases into harmless nitrogen and water. This means your vehicle will emit more harmful exhaust pollutants.
4
Warning lights and limp mode:
Vehicles with SCR systems monitor AdBlue quality. Using degraded or contaminated fluid can trigger dashboard warnings and eventually put the vehicle into a reduced-power limp mode.
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Buy only what you need:
To avoid waste, buy AdBlue in a quantity you will realistically use within 12 months. Small 5–10 litre containers are widely available at petrol stations and motor factors.
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Keeping Your Diesel Running Efficiently
Top up before the warning light:
Most diesel cars give a warning when AdBlue drops below around 1,500 miles of range. Topping up early avoids the risk of running out and being unable to restart the engine.
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Check fuel costs too:
Running a modern diesel efficiently includes keeping fuel costs down. CheckFuelPrices shows live diesel prices at 4,000+ UK stations so you can find the cheapest pump near you.
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Sources
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