Diesel engines are beasts. They’re powerful, reliable, and efficient. But they require a little more care than gasoline engines to keep them running smoothly. One of the most important parts is diesel exhaust fluid or DEF for short.
Diesel exhaust fluid (DEF) is a byproduct of the diesel engine and contains water, urea, and other chemicals. It can be used in conjunction with your truck’s emission system to help reduce nitrogen oxide emissions.
The best DEF for Duramax trucks is one that will last longer than others due to its high-quality formula and provide optimum performance with minimal maintenance required.
To save yourself from having to worry about it, make sure you’ve got the best def fluid for your Duramax. We’ll show you what’s out there and how to pick the right one so that you can get back on the road in no time.
- 1 What is Diesel Exhaust Fluid?
- 2 Best DEF Fluid For Duramax – Our Top 5 Picks
- 2.1 1. Blue Def DEF002-2PK Diesel Exhaust Fluid
- 2.2 2. Prestone HD1001-2PK Command Diesel Exhaust Fluid
- 2.3 3. ACDelco GM Original Equipment 10-4023 Diesel Exhaust Emissions Reduction (DEF) Fluid
- 2.4 4. Genuine Ford Fluid PM-27-JUG Diesel Exhaust Fluid
- 2.5 5. Valvoline 729566-2PK Premium Blue Diesel Exhaust Fluid
- 3 Buying Guide for Best Diesel Exhaust Fluid
- 4 FAQs
What is Diesel Exhaust Fluid?
Diesel Exhaust Fluid (DEF) is a mixture of 75% distilled deionized water and 25% high purity urea. The production rate of DEF varies between manufacturers but is typically around 6 gallons per hour.
The objective of this process is to remove the nitrogen oxide present in the diesel exhaust. Nitrogen oxide or NOx is a result of diesel engine combustion and is a pollutant. The DEF mixture is sprayed into the exhaust stream where it absorbs the NOx from the exhaust, turning it into harmless nitrogen gas or N2.
The baffle above prevents any fluid that has not been completely atomized from dripping down onto other components in the exhaust system while the baffle below directs the exhaust flow and spray pattern.
Most aftermarket DEF fill tanks are similar in design and function. The primary differences will be how the pump and nozzle fit onto your DEF tank.
Some systems attach directly to a DOT 3, 4, or 5-gallon container while others use a barb fitting to connect to the smaller DEF cans.
No matter what system you choose, make sure the one you buy will fit your DEF container.
The nozzle design is also important. When filling a DEF tank you want to make sure the pump doesn’t overfill or spill fluid onto other components in the exhaust system which can damage sensitive catalytic converters and O2 sensors. Even with the proper nozzle, you should take extra precautions and double-check your work!
The DEF tank is fitted to the exhaust system downstream of the turbo. The system shown here uses a simple barbed fitting between the DEF fill tank and the DEF nozzle. Depending on your fill method, this may or may not be necessary.
The key to successfully filling a diesel exhaust fluid tank is to make sure you don’t overfill.
A small amount of diesel exhaust fluid will be needed even after the DEF tank is full, so make sure you go back and check your work!
Best DEF Fluid For Duramax – Our Top 5 Picks
The best def fluid for Duramax can be quite a task to find. With so many brands and considerations, it can become overwhelming quickly.
We have researched and found some of the best diesel exhaust fluids on the market today so that you don’t have to waste time trying out different brands.
Let’s look at the top 5 picks and break down their benefits to hopefully make things easier for you.
Fortunately, our blog post will help you decide which is the right one for your vehicle!
1. Blue Def DEF002-2PK Diesel Exhaust Fluid
- Meets ISO Standards 22241
- Meets EPA 2010 regulations
- It can go up to 6000 miles between fill-ups
Diesel exhaust fluid is used in diesel engines to burn up unhealthy carbon emissions and provide a clean, smooth horsepower. One gallon lasts about 300 miles with one application.
A 20-gallon tank of DEF will let you go up to 6000 miles between fills, which means that it can help make sure your vehicle runs smoothly and efficiently every time out on the route with one less stop at a service station or gas station— saving money in both cases.
Diesel Exhaust Fluid is an important part of reducing the levels of NOx emissions from your engine.
It can be used in conjunction with Selective Catalytic Reduction SCR systems, which helps engines meet new EPA regulations.
They are designed specifically for this purpose and work hard at reducing smog-forming chemical compounds like carbon dioxide or hydrocarbons into harmless precursors through chemical reactions inside their combustion chambers.
Blue Def is a liquid that helps convert NOx into harmless and natural components of the air.
It does not contain any fuel or additive, instead, it works by injection when passed over catalysts to break down harmful emissions from diesel engines as they pass through your vehicle’s exhaust system – before those molecules can enter our lungs!
The product also meets ISO standards for purity with API certification proving its cleanliness against toxins found in popular fuels on today’s marketplace
Blue DEF will help you stay on top of your game with safety and quality in mind because it exceeds emissions standards for optimum SCR’s effectiveness!
Truck owners know that regular maintenance is key to ensuring their safety and peace of mind on the road.
One important part of this process, which can seem simple or difficult depending on who you ask, includes checking your Diesel Exhaust Fluid (DEF) levels before refilling with fuel- it should never be done without.
The gauge will tell when it’s time for a refill as longs there’s enough left in either tank–just make sure not all other fluids get contaminated.
- High Quality
- Easy to Use
- Value for Money
- Bit expensive
2. Prestone HD1001-2PK Command Diesel Exhaust Fluid
- Certified to meet all API & ISO 22241 requirements
- Easy-pour bottle
- Work with all SCR-equipped diesel engines
With the appearance of new diesel engine technology, Prestone Command DEF is formulated to work with all SCR-equipped engines.
It can be handled safely without any problems or worries about exposure and it does not contain toxic chemicals like urea which makes for an easy disposal process.
Once properly disposed of in a licensed facility according to its certification by both API/ISO standards making this product is essential as well as consumable fluid when maintaining your car’s performance under optimal conditions every time you go out driving around town.
It is a solution of 67.5% water and 32.5%, or automotive-grade urea that can be used in all types of diesel engines equipped with Selective Catalytic Reduction technology for increased fuel efficiency without compromising on emissions compliance standards
Diesel Exhaust Fluid (DEF) maintains optimal engine performance by absorbing harmful gasses released during operation like carbon monoxide, hydrocarbons, etc.
While reducing oxides of nitrogen which lead to the formation of particulate matter under certain conditions when not managed properly due to high temperatures caused by friction between air turbulence incoming from outside sources where there are no veils present either way around it.
This is a must-have for any car with a diesel engine. It helps reduce harmful emissions and can be used at concentrations up to 3% of fuel consumption, which equals one gallon per 50–75 gallons in your tank.
On average that’s how much it will last you during regular driving conditions but it all depends on where the vehicle lives (how fast they go).
- Easy to Handle
- Relatively Low consumption
- Good value for money
- Shelf life is reduced to 1 year if stored at 80 degrees
3. ACDelco GM Original Equipment 10-4023 Diesel Exhaust Emissions Reduction (DEF) Fluid
- Meets the ISO 22241 standard
- It comes with a free nozzle
- Environment-Friendly Product
It is a powerful, stable, and safe chemical that can be used to help convert NOx, an environmental pollutant into harmless nitrogen and water.
ACDelco meets the specifications of both GM Original Equipment and Non-GM Diesel vehicles. They are approved for use in your car with SCR systems, so you can have more confidence when it comes time to get an oil change.
Its high-quality urea and deionized water formula are made from 100% natural ingredients, making it an environmentally friendly product.
Its Diesel’s high purity synthetic urea makes up almost all of the mixture while deionized water helps balance out other components such as acids needed for combustion byproducts like smog-forming hydrocarbons better than just adding more natural gas could ever hope too.
The absence of any chemical additives or other components can cause SCR system failure in the engine which will benefit your car’s performance on gas.
Its parts are designed to provide you with quality and performance. They come equipped with vented nozzles that make pouring easy by preventing glugging, which can be an issue when using standard parts on your car or truck.
It has a free nozzle for your convenience. Extra nozzles are available and can be ordered separately, so you’re guaranteed to find the right fit with these parts.
- High Quality
- Easy Pouring
- Long shelf life
- The tube did not come with it to make pour simple
4. Genuine Ford Fluid PM-27-JUG Diesel Exhaust Fluid
- Specifically designed Nozzle
- Meets standards of ISO 22241 and DIN70071
- Meets strict EPA environmental Standards
It is a type of chemical that helps your vehicle run more efficiently by decreasing emissions. It can be used for all diesel vehicles equipped with an SCR system, so you don’t have to worry about being caught without it on public roads!
This is an essential part of any diesel vehicle with an SCR catalyst. This product helps reduce NOx emissions by capturing unburned gasses before they enter into our atmosphere, reducing pollution, and improving air quality for drivers everywhere.
It is high quality and trusted product. It meets all of the requirements to be ISO 22241, DIN70071 certified for use in diesel engines which means its purity standards allow it to deliver better performance as well as reduced emissions when compared with other fluids on the market today
If you’ve had the unfortunate experience of spilling your diesel exhaust fluid on a new car, then this nozzle is what’s for sure going to get it cleaned up in no time.
When installing one side may be difficult and should only require moderate wrenching skills while others can easily twist off thanksgiving turkey-style.
If your car or truck was built after January 2010, it needs a Genuine Ford Fluid Diesel Exhaust Fluid (DEF) to destroy harmful emissions.
It’s used to destroy harmful emissions in the exhaust while meeting EPA strict environmental standards so you can drive with confidence knowing that your engine has been thoroughly checked for cleanliness too!
DEF helps meet new environmental standards set by the EPA and protects our air quality for those who breathe in its fumes while driving down the road without any particle pollution like soot from fuel combustion engine exhaust systems.
- Smoking cessation abilities
- High Quality
- Some of the products don’t come with a nozzle
5. Valvoline 729566-2PK Premium Blue Diesel Exhaust Fluid
- Meets ISO 22241 specification
- API and AdBlue certified
- Blue Color
This blue diesel oil is manufactured to the most stringent production specifications, which are above and beyond typical engine oils.
The new formulation has been tested in SCR-equipped diesel engines using the latest in emissions control technology under some of the harshest operating conditions.
This was developed with America’s top off-road and heavy-duty equipment manufacturers that demand the highest level of lubrication performance.
This DEF is API and AdBlue certified, has ISO 22241 certification for use in SCR-equipped diesel engines operating in some of the harshest environments, including the northern regions of North America where temperatures can drop to -30 degrees Celsius.
It is engineered with a high Viscosity Index (VI) that helps to ensure protection when temperatures are low.
This product has been manufactured using only dedicated equipment which ensures there will be no impurities in this high-performance engine lubricant for your vehicle needs!
- Superior wear protection to help your engine run strong and last longer.
- Excellent low-temperature performance for smooth shifting and outstanding anti-shudder/stall protection in cold climates.
- Maximum oxidation stability for enhanced fluid life and longer intervals between oil changes.
- Packaging may get damaged during shipping
Buying Guide for Best Diesel Exhaust Fluid
These are some of the important features to look for when buying the best Def fluid for Duramax
The fluid you pick should be stable and has no water or other contaminants in it. This means that the fluid will last a long time without degrading.
So, look for something that has been around for a while and which has stood the test of time.
Your DEF fluid needs to process quickly for your vehicle to remain in compliance with the law. So, make sure you pick something that can process quickly.
Otherwise, you will have a hard time keeping up with the fluid levels while on the go.
The DEF fluid you pick should be one that can pour easily and is not too thick or viscous. This will help you not have any spilling issues while refilling.
The fluid should be clean and pure so that it does not lead to corrosion or another buildup on your vehicle’s components.
You want something free of contaminants, especially water because this will speed the degradation process up immensely.
Look for one which also has a high lubricity rating. This will help reduce wear and tear on various components like the injection pump, injectors, etc.
The DEF fluid you pick should have corrosion protection with withstands the chemical makeup of the additive which is needed to process urea.
Look for an alkalinity rating of around 120-150 ppm so that you have a fluid with high alkalinity to keep the injectors clean and the whole system free of corrosion.
The DEF fluid should have good electrolytic stability because it will help lengthen the life of parts like the alternator, starter, etc.
It should not contain acids, rusting agents, or other chemicals which can wear down these parts quickly.
Your DEF fluid should be non-toxic and environmentally safe if you are worried about spilling it on your vehicle’s paint job.
Look for something that is not harmful to the environment as well as your paint job in case you spill some.
The DEF fluid which you pick should be able to hold up in extreme weather conditions and not break down or become too viscous at high temperatures.
This will help it work better when it’s hot outside and also avoid issues like clogging around the injection pump when the temperatures drop.
Your DEF fluid should be one that can withstand high temperatures well. This is because it will help prevent issues like clouding in cold weather when the fluid becomes too viscous, clogging around the injection pump, and also hardening or gelling at low temperatures which can affect performance.
Look for something with a temperature range of between -35 degrees Fahrenheit to +215 degrees Fahrenheit.
Filler Neck Compatibility:
The DEF fluid should be one that can fit in your filler neck and also have a high pour rate. This will help avoid spillage from the top when you are refilling it.
So, look for something which is not too tall and has a pour rate of at least 97+% so that you can more easily top off the fluid levels on your vehicle.
Ease of Use:
Your DEF fluid should be easy to use, maintain, and refill.
This means that it needs to have good user manuals with clear instructions on maintaining it, cleaning it up if there are any spills, and also refilling it.
Your DEF fluid should be compatible with your vehicle’s type of DEF system.
It needs to not damage the sensors which are already in place or interfere with the readings that these systems provide.
Make sure you check compatibility before you commit to a particular brand or type of fluid.
With the help of these tips, you should be able to make an informed decision on which DEF fluid is right for you.
Remember to consider your truck’s engine type and what kind of driving conditions it experiences before making a final decision. And if all else fails, remember that Prestone Command Diesel Exhaust Fluid was built with diesel trucks in mind.
Prestone Command Diesel Exhaust Fluid is the best DEF fluid for Duramax. This high-quality diesel exhaust fluid can be used to make a variety of trucks, buses and other motorized vehicles run more efficiently by reducing engine wear and ensuring that they produce fewer emissions.