What is diesel exhaust fluid?

[RaydaKub]

I just heard a commercial on the radio for Dodge pickups the announcer said "... and you won't have to burn diesel exhaust fluid until 2013."
One can easily surmise this has something to do with emissions, but what is diesel exhaust fluid? Will you have to buy a bottle of additive every time you fill up (sorta defeats the pay-at-the-pump idea) or will they just dump it into the fuel tank and jack up the price another 15 cents? How will it affect older engines? Is it also required for off-road?

 

[firemanpat2910]

DEF is stored in a tank on board the vehicle, and injected into the exhaust stream by a metering system at a rate of 2% of diesel consumption volume. This low dosing rate ensures long fluid refill intervals and minimises the tank's obtrusion into vehicle packaging space. An Electronic control unit adjusts the addition of fluid in accord with such parameters as engine operating temperature and speed.

Diesel Exhaust Fluid is offered to consumers through a variety of quantities by manufacturers ranging from containers of it for single or repeated small usage to bulk carriers for consumers that require a large amount DEF. It's recommended that it be stored in a cool, dry, and well-ventilated area that is out of direct sunlight.

copied from wikipedia

 

[k0ua]

More than you ever wanted to know about DEF

2011 Ford Super Duty Diesel Exhaust Fluid (DEF) Tutorial - YouTube

James K0UA

 

[Gary Fowler]

DEF= Just another reason not to buy a diesel.
MY question is what happens if you dont put any DEF in the tank, does it shut down the engine. That would be bad if out in the middle of nowhere and ran out.

 

[mikehaugen]

DEF= Just another reason not to buy a diesel.
MY question is what happens if you dont put any DEF in the tank, does it shut down the engine. That would be bad if out in the middle of nowhere and ran out.

while I agree, it is still no different than running out of fuel... just have to make sure it doesn't happen. Besides (though I don't own a diesel and can't say for sure) I doubt that it would shut off the engine, I am guessing there is some sort of indicator like a check-engine light. It may even trigger the check engine light.

 

[Mechanos]

DEF= Just another reason not to buy a NEW diesel.
...

I couldn't be happier with my '01 Cummins powered 3/4T.

 

[Gary Fowler]

I am just starting to see DEF available at Farm and Ranch supplies. I havent seen it at any service stations , maybe it is at larger trucker stops. Looks like that tank sensor would be the first thing I would jumper to make it think it was always full. There should be much easier way to make a diesel engine run cleaner than adding urea to the exhaust.
On the other side of the environment coin, I think the video said it was a 95/5 mixture of urea and water. Isnt that a type of nitrogen fertilizer? Just buy a big tank of urea and mix your own for pennies per gallon

 

[eagle107]

I am just starting to see DEF available at Farm and Ranch supplies. I havent seen it at any service stations , maybe it is at larger trucker stops. Looks like that tank sensor would be the first thing I would jumper to make it think it was always full. There should be much easier way to make a diesel engine run cleaner than adding urea to the exhaust.
On the other side of the environment coin, I think the video said it was a 95/5 mixture of urea and water. Isnt that a type of nitrogen fertilizer? Just buy a big tank of urea and mix your own for pennies per gallon

I have been seeing DEF offered at many of the PA Truck Stops when I stop for fuel while driving between NJ and Buffalo, NY.

 

[mikehaugen]

On the other side of the environment coin, I think the video said it was a 95/5 mixture of urea and water. Isnt that a type of nitrogen fertilizer? Just buy a big tank of urea and mix your own for pennies per gallon

or just recycle after drinking a lot coffee....:thumbsup:

 

[crowbar032]

DEF= Just another reason not to buy a diesel.
MY question is what happens if you dont put any DEF in the tank, does it shut down the engine. That would be bad if out in the middle of nowhere and ran out.

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.