Diesel Exhaust Fluid (DEF) is used in modern diesel engines to reduce pollution. But DEF needs to be high quality to work properly and avoid damaging the engine’s emissions system.
DEF specifications are governed by the ISO 22241 standard. Let’s learn more about what that means.
ISO 22241: Defining DEF Quality
The ISO 22241 standard sets the bar for DEF quality. Here’s a quick look at what’s important:
Key Chemical Properties
DEF is mostly water and urea. It’s supposed to be a 32.5% urea solution (plus or minus 0.7%). The standard also sets limits on how much of other stuff can be in there, like ammonia, biuret, and aldehydes.
Physical Characteristics
DEF also has to meet certain physical requirements. For example, the density has to be between 1.0870 and 1.0930 g/cm3 at 20˚ C. The refractive index (how light bends when it passes through the liquid) also has a specific range: 1.3814-1.3843 at 20˚ C.
Why are DEF specs so important?
Using DEF that doesn’t meet ISO 22241 standards can seriously damage your SCR system. Impurities can poison the catalyst and make the whole system less efficient.
So, how do you make sure you’re using quality DEF? Simple. Ask your supplier for a Certificate of Analysis (C-of-A). This document proves the DEF meets the required specs. You can also send DEF samples to a lab for testing to verify urea concentration, density, and impurity levels.
Frequently Asked Questions
What is a good DEF quality percentage?
When it comes to DEF (Diesel Exhaust Fluid), aiming for the highest possible quality is always the best approach. You’re generally looking for a DEF that meets or exceeds the ISO 22241 standard. In practical terms, this means a DEF that’s consistently above 32.5% urea concentration is ideal. While minor fluctuations might occur, you want to avoid DEF that consistently dips below this threshold. Lower quality DEF can lead to reduced performance of your SCR system, potential damage, and increased emissions. So, think of it like this: higher DEF quality equals better performance and a healthier engine!
Is DEF fluid just salt water?
Absolutely not! While it might look like water, DEF is definitely not just salt water. It’s a carefully crafted solution of high-purity urea (32.5%) and deionized water (67.5%). The deionized water is crucial because any impurities could damage the Selective Catalytic Reduction (SCR) system. Think of it like comparing tap water to distilled water – both are water, but they have vastly different compositions and uses. Using something like salt water in place of DEF would be disastrous for your vehicle’s emission control system, potentially leading to costly repairs. So, always stick with the real deal!
In Closing
Sticking to DEF specifications, especially ISO 22241, is super important for keeping your diesel engine running smoothly and cutting down on emissions. Regular testing is key!