Share this:
Diesel Exhaust Fluid (DEF) is an essential component in modern diesel engines, helping to reduce harmful emissions and comply with environmental regulations. If you're new to DEF, this guide will explain what it is, how it works, and why it’s crucial for diesel vehicle owners and fleet operators.
What is Diesel Exhaust Fluid (DEF)?
DEF is a high-purity, non-toxic solution composed of 32.5% urea and 67.5% deionized water. It is specifically designed for use in Selective Catalytic Reduction (SCR) systems, which are found in most modern diesel engines. DEF is not a fuel additive; it is stored in a separate tank and injected into the exhaust system to reduce emissions.
How does DEF works?
DEF plays a key role in reducing nitrogen oxide (NOx) emissions, which contribute to air pollution and smog. Here’s how it works:
Injection into the Exhaust System: DEF is sprayed into the exhaust stream of a diesel engine before it reaches the SCR catalyst.
Chemical Reaction: When exposed to heat, DEF breaks down into ammonia (NH3) and carbon dioxide (CO2).
Conversion of NOx: The ammonia reacts with NOx in the SCR catalyst, converting it into harmless nitrogen (N2) and water vapor (H2O).
Emission Reduction: The result is a significant reduction in NOx emissions, allowing diesel engines to meet strict environmental regulations like EPA and Euro 6 standards.
Benefits of using DEF
Using DEF in diesel vehicles provides several important advantages:
Reduces harmful emissions: DEF significantly lowers NOx emissions, making diesel engines more environmentally friendly.
Compliance with Regulations: SCR-equipped vehicles using DEF meet stringent emission standards, avoiding fines and restrictions.
Improved fuel efficiency: Because engines with SCR technology run more efficiently, they consume less fuel compared to older diesel models.
Extended engine life: DEF helps maintain engine components by reducing soot buildup and wear caused by high NOx levels.
Better performance: Vehicles running on SCR technology with DEF experience smoother operation and better overall performance.
How to use and store DEF
To ensure optimal performance, follow these best practices for handling and storing DEF:
Use certified DEF: Always use DEF that meets ISO 22241 standards, such as Noxguard DEF, to avoid contamination and damage to the SCR system.
Store properly: DEF should be kept in a cool, dry place away from direct sunlight. Ideal storage temperatures range between 12°F (-11°C) and 77°F (25°C).
Check expiry dates: DEF has a shelf life of 12-24 months, depending on storage conditions. Using expired DEF can reduce its effectiveness.
Avoid contamination: Never mix DEF with other fluids like fuel or water, as this can compromise its performance and damage the SCR system.
Common myths about DEF
There are many misconceptions surrounding DEF. Here are a few common myths debunked:
Myth: DEF is a fuel additive.
Fact: DEF is stored in a separate tank and never mixes with diesel fuel.
Myth: DEF is toxic and hazardous.
Fact: DEF is non-toxic, non-hazardous, and safe to handle.
Myth: You can use water instead of DEF.
Fact: Using anything other than certified DEF will damage the SCR system and void warranties.
Myth: DEF reduces engine power.
Fact: SCR systems with DEF actually improve engine efficiency and fuel economy.
Discover more myths and realities
Why choose high-quality DEF from Noxguard?
all DEF products are created equal. Noxguard provides high-purity DEF that meets ISO 22241 standards, ensuring optimal performance and longevity for your diesel engine. Our DEF is rigorously tested to prevent contamination, making it the best choice for fleet operators and individual diesel vehicle owners.
