How Long Does DEF Last In 6.7 Powerstroke on average?

Nowadays, where keeping the environment clean is paramount, Diesel Exhaust Fluids (DEF) are important parts of the engine. Every diesel engine, like the 6.7 Powerstroke has DEF, which lasts for different times depending on the engine. So how long does DEF last in 6.7 Powerstroke? On average, the DEF in a 6.7 Powerstroke lasts 5000-6000 miles.

Apart from the distance, there is another way to find out the lifespan of the DEF of an engine. The rate of consumption of the DEF is 2-3% of that of the fuel. So, if you know how much diesel you’re using, finding out how long DEF lasts isn’t too hard.

Amount of Fuel38 gallons
Amount of DEF0.76 to 1.14 gallons

DEFs help keep the emission levels to a minimum through a process known as SCR. This process ensures that NOx gas, which is harmful to the environment, isn’t released to the environment. There are a couple of ways to check whether the DEF levels are up to the mark. First, there is a warning system installed in the dashboard. You can also check it manually.

What Is A DEF And How Does It Work?

Before going into details of the lifespan of DEF in 6.7 Powerstroke, let’s know a bit about what it is. DEF or Diesel Exhaust Fluids are fluids that help reduce emission levels by not allowing NOx gas to be released into the environment.

Nitrogen oxide gases are detrimental to the environment for many reasons. They not only damage crops, but are also a major reason for acid rains. And one of the major sources of NOx was diesel engines.

That’s where the DEF comes into play. These fluids break the NOx down via a process named SCR (Severe Catalytic Reaction). This process ensures that NOx doesn’t get released into the atmosphere directly.

Rather than releasing the gas directly through the exhaust, the SCR redirects the NOx to enter a filter. There the DEF breaks the NOx down into two parts: Nitrogen and water. These are then released into the air, which doesn’t harm the air at all.

How Long Does DEF Last In 6.7 Powerstroke?

Now, as the DEF constantly works to break the NOx down, they eventually run out. So, you have to replace the DEF in your 6.7 Powerstroke. There are a couple of ways you can determine when to replace Powerstroke’s DEF.

First, you can use the traditional method of using the distance as a parameter. Usually, the DEF in a diesel engine like the 6.7 Powerstroke lasts about 5000 to 6000 miles. So, once you reach the required distance, you know that DEF in your engine won’t work at its best anymore.

There is another, more precise way to determine how long your 6.7 Powerstroke’s DEF lasts. The DEF is used up at a rate that is 2 to 3 percent of the rate your fuel is used up. So, if you know how much fuel you need before refueling, you need to multiply the amount by 0.02 or 0.03.

The amount you will get is the amount the DEF is being used every time you fill up your tank. This method is better as different engines use fuels at different rates due to a lot of factors. So having a set amount isn’t exactly the correct way to operate.

How Do You Know That The DEF Needs Changing?

Since the DEF eventually loses its ability to break down the NOx, it has to be replaced when that happens. There are two ways you can know that you have to replace your 6.7 Powerstroke’s DEF.

Since 2010, all diesel trucks have been equipped with a warning system in their dashboards that shows the DEF levels. So, when the levels of the DEF start to under 10%, the drivers are continuously alerted until they fill up the DEF.

Apart from this, you can also check the DEF levels manually. You can learn how to do this from here.

How To Ensure DEF Quality?

Sometimes the DEF’s quality drops which causes a lot of issues for the vehicle. There are a few ways to prevent the DEF from going bad. They are-

  • Keeping up to date with the shelf life.
  • Storing the DEF in proper containers.
  • Keeping it away from direct sunlight.
  • Keeping the nozzle of the container clean.
  • Handling with care.

Frequently Asked Questions (FAQs)

1. How Much DEF Does A Ford 6.7 Use?

The Ford 6.7 Powerstroke uses about 8 gallons or 30.2 liters of DEF. But you don’t have to refill your DEF now and then. The consumption rate of the DEF is very low, so filling up the DEF every third time you refuel is enough.

2. How Many Miles Will 1 Gallon Of DEF Last?

The DEF lasts about 300 to 500 miles per gallon. This value varies from engine to engine. In comparison, a gallon of diesel lasts about 6.5 to 7.5 miles. So, depending on the engine, a gallon of DEF lasts about 45 to 66 times a gallon of diesel.

3. Is Platinum Blue DEF Better?

Every kind of DEF is almost the same, with some minor modifications. So, the platinum blue DEF isn’t something too special when compared to other DEFs. The only thing that makes it somewhat different from others of its kind is the presence of platinum which prevents crystallization.

Final Words

As DEF is one of the most important parts of diesel engines, people often wonder, ‘how long does DEF last in a 6.7 Powerstroke?’It lasts anywhere between 5000 and 6000 miles. The rate of consumption of DEF is about 2-3% of the fuel consumption rate. So, you can also calculate it that way

The DEF is becoming more and more important as the years go on due to the rising threat of global warming and environmental pollution. There are a couple of ways to check the DEF levels and when to replace them.

Who Worked on This?



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Mahir Ahmed


I'm the guy responsible for ensuring honest, informative, accurate and helpful guide to the reader.

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