What is diesel exhaust fluid?

[greasemonkeyok]

Limp mode. Humph, guess I need to refill my DEF tank.

 

[RaydaKub]

My neighbor just bought a new Chevrolet 1 ton dump truck and I asked him the same question. There is a DEF monitor on the dash that tells how many gallons are left in the tank. Once it gets so low, an idiot warning light comes on. When/if it runs out, the truck will only run at 14 MPH or less. It basically goes into limp mode until you refill the DEF tank. So while not technically dead, it would still seriously suck if you ran out in the middle of nowhere.

OK, I watched the video. If the tank is full, the dash says OK. If the tank is 1/2 full or less, it reminds you to refill. Then there is an 800 mile warning. Then at 300 miles it limits you to 55 mph. Once it is dry, it keeps it at an idle. It would suck to run out, but geez, you certainly had enough time to do it no matter where you were going.

Points of failure and other purchase/repair costs aside, I guess I'm still wondering how this works. Not sure how much a gallon of it is either. I guess there are quite a few more videos out there if I wanna take the time to watch them.

But I had never heard of it before this morning, now I'm half educated. Thanks fellas. I love these forums.

 

[B Hoofed]

We have a 2011 F350 diesel that uses DEF. It's really no problem at all to deal with. The tank holds 10 gallons, which is enough for 5-10 thousand miles depending on the type of driving. It's easy to fill the tank and you can get a 5 gallon bottle for $10 - $15 at most auto parts stores or Walmart. The DEF allows the truck to get much better fuel economy, which outweighs the additional cost of the DEF. The only negative I see is added complexity to an already complex powertrain, and one more system to fail. The early 6.7 powerstrokes have had some issues with DEF pumps and sensors failing.

 

[Patches]

Limp mode. Humph, guess I need to refill my DEF tank.

Holy cow pi$$, batman

 

[k0ua]

Holy cow pi$$, batman

Maybe that would work... it is about the same stuff

James K0UA

 

[Buckgnarly]

We have a 2011 F350 diesel that uses DEF. It's really no problem at all to deal with. The tank holds 10 gallons, which is enough for 5-10 thousand miles depending on the type of driving. It's easy to fill the tank and you can get a 5 gallon bottle for $10 - $15 at most auto parts stores or Walmart. The DEF allows the truck to get much better fuel economy, which outweighs the additional cost of the DEF. The only negative I see is added complexity to an already complex powertrain, and one more system to fail. The early 6.7 powerstrokes have had some issues with DEF pumps and sensors failing.

The DEF is injected into the exhaust to reduce NOx emissions, how do you figure it increases mileage if it is used post detonation?

Edit: nevermind, I see that it can allow the engine to be tuned different....do you really see an appreciable difference in mileage?

 

[Pharm]

Is there talk of putting this on tractors of the future? This is the first I've heard of diesel exhaust fluid - thanks for the education.

 

[k0ua]

Is there talk of putting this on tractors of the future? This is the first I've heard of diesel exhaust fluid - thanks for the education.

Supposed to be on next years models. or some method of reducing emissions to meet Tier 4 Final specifications. We shall see.

James K0UA

 

[Bigkrank]

Already on tractors and combines around here.

DEF system can increase fuel mileage on trucks compared to just DPF only technology because it allows for fewer regens, regens use fuel to burn soot out of DPF. With DEF being injected regens happen less frequently.

I know I love pulling a white enclosed trailer that no longer has a black streak going down the side of it.

 

[RaydaKub]

Holy cow pi$$, batman

I know I love pulling a white enclosed trailer that no longer has a black streak going down the side of it.

Ummm, does it have a yellow streak going down the side instead? :laughing: