According to the U.S. Bureau of Transportation Statistics, fewer than 5% of the passenger cars and trucks that are out on the road today use diesel. As a result, the vast majority of people won’t ever have to worry about their DEF fluid levels.
But if you happen to drive a diesel-powered passenger car or truck or if you have a commercial vehicle that runs on diesel, you’re going to need to know what DEF fluid is. You’re also going to need to know what might happen if you attempt to drive a diesel vehicle without any DEF fluid in it.
Today, we’re going to speak directly to all the diesel-powered vehicle owners out there about the importance of DEF fluid. You should make sure that you listen up if you rely on a diesel car or truck to get you from point A to point B.
Here is everything you need to know about DEF fluid.
What Is DEF Fluid?
If you drive around in a diesel-powered vehicle on a regular basis, we hope that you’ve at the very least heard of DEF fluid before. But just in case you don’t know what it is, we’re going to start there in our discussion on it.
DEF fluid is a non-toxic fluid that is a mixture of about two-thirds deionized water and one-third Urea. It’s designed to help reduce the dangerous NOx emission gases that a diesel engine can produce. It turns these harmful gases into water and nitrogen so that they won’t do any damage to the planet as they head out into the world through a diesel vehicle’s exhaust system.
There is a blue DEF fluid cap that will indicate where DEF fluid should be put in a diesel vehicle. It’s imperative that you keep the DEF fluid tank filled with DEF fluid and not diesel itself.
How Does DEF Fluid Work?
Now that you have a little bit of a better idea as to what DEF fluid is, it’s time to touch on what it does in the context of your diesel vehicle. It’ll help you to wrap your head around why it’s so imperative that you keep enough DEF fluid in your diesel vehicle at all times.
Here is the process that plays out that allows your vehicle’s DEF fluid to do its job:
- Your vehicle’s diesel engine produces exhaust gases that leave your combustion chamber filled with nitrogen oxide, sulfur dioxide, and carbon monoxide
- These exhaust gases make their way through a particulate filter that takes any soot or ash found in them out
- These exhaust gases then move past a nozzle that sprays them down with DEF fluid
- The exhaust gases and the DEF fluid push their way into your diesel vehicle’s catalytic converter
- The DEF fluid takes the exhaust gases and transform them into water and nitrogen
As you can see, the DEF fluid in your diesel-powered vehicle plays a big part in the reduction of dangerous exhaust gases. Without enough DEF fluid, your diesel vehicle will push these gases out into the world, which will make your vehicle a lot less eco-friendly than it should be.
What Happens If You Drive a Diesel Vehicle Without DEF Fluid?
As you begin to run low on DEF fluid in your diesel vehicle, you’re going to notice some changes in the way that it runs. At first, it’s going to feel a lot more sluggish than it normally does. But that won’t be the last sign that will indicate a lack of DEF fluid in your DEF fluid tank.
From there, your diesel-powered vehicle will also begin to slow down on you, and eventually, it won’t go over 5 miles per hour. At some point, a red warning light will also turn on to let you know that you’re officially out of DEF fluid. And these symptoms won’t go away until you’ve added DEF fluid to your vehicle.
You’ll need to Google “DEF fluid near me” ASAP so that you can find DEF fluid at Walmart or another store in your area. Or better yet, you can go ahead and click here now to see how you can have DEF fluid delivered right to you.
How Much DEF Fluid Does a Diesel Vehicle Need?
If you’re going to add DEF fluid to your diesel vehicle, you shouldn’t just guess how much that you’ll need to add to it and run with that. Instead, you should figure out exactly how much DEF fluid your specific diesel vehicle needs.
You should be able to see how much DEF fluid that your vehicle needs by consulting your owner’s manual. You might also be able to speak with a mechanic to get some sense of how much DEF fluid you should be adding to your diesel vehicle.
How Often Should You Add DEF Fluid to a Diesel Vehicle?
In addition to finding out how much DEF fluid you will need to add to your diesel vehicle, you should also determine how often you’ll need to add DEF fluid to it. Generally speaking, you’re going to have to add DEF fluid to your vehicle at least once every few months.
It will depend on how large your DEF fluid tank is and the fuel economy of your vehicle. But many diesel-powered vehicles will call for you to add between two and three gallons of DEF fluid every 10,000 miles or so.
Make Sure Your Diesel-Powered Vehicle Always Has DEF Fluid in It
Diesel and DEF fluid go hand in hand. If you’re going to drive a diesel vehicle, you’ll need DEF fluid to go along with it.
You should stop driving your diesel vehicle immediately if you sense that you’re low on DEF fluid. You should also get yourself into the habit of checking your DEF fluid tank to see how much DEF fluid you have left. Doing these things should help you avoid having to worry about running out of DEF fluid at any point.
Get more tips on driving a diesel-powered vehicle by taking a closer look at some of our other auto-related blog articles.