DEF (Diesel Exhaust Fluid), One size fits all?

[Jim Koepke]

The consequence, in my opinion, should just be a check engine light. Can get cleared when refilled, or when any fault gets corrected. Low power mode is a dangerous action for a system that isn’t damaging to the drivetrain.
But to more directly answer your question- a good many probably. there are a lot of gasoline check engine lights illuminating the lands out there that not many are interested in fixing.

Click and Clack on Car Talk used to joke about black tape to fix the check engine light. My car tells me to change engine oil if resetting the computer is forgotten.

DEF is what allows us to use diesel without putting a lot of noxious gasses in the atmosphere. Some people do not care about such things.

Before a vehicle goes into low power mode is there a gauge or other warning that it is getting low?

It may be the only way some people will bother to keep an eye on the DEF tank level is if there is a draconian way to make them pay attention.

jtk

[Rob Luter]

When I got my diesel sedan I was a bit miffed at the DEF issues too. Mine will actually shut the car off if you run dry. You get a warning light about 1000 miles in advance. That said, a tank lasts about 10K miles and it's easy to just top it off when changing the oil. The stuff is cheap and easy to add. I like that it takes NOx out of the exhaust. I like that my exhaust has no odor. My car gets 40 MPG in mixed driving and 50 MPG on the freeway. A 15 gallon tank of fuel will last 600 miles daily driving and 700 miles on a trip. Lots more upside to downside. What chaps my hide is that they (BMW, VW, Benz) are not bringing diesels into the US any more. This whole VW fiasco and the decision that electric cars are the future has made them unavailable unless you want to buy a massive pickup.

[Adam Grund]

I like that my exhaust has no odor.

Mine would smell. Def’d mine smelled like ammonia. While Smells are subjective, for short idling like if I were hooking up a trailer- I still prefer diesel fuel exhaust to a def exhaust. It would make me nauseous if I had to smell it longer than a min or so.

Click and Clack on Car Talk used to joke about black tape to fix the check engine light. My car tells me to change engine oil if resetting the computer is forgotten.

DEF is what allows us to use diesel without putting a lot of noxious gasses in the atmosphere. Some people do not care about such things.

Before a vehicle goes into low power mode is there a gauge or other warning that it is getting low?

It may be the only way some people will bother to keep an eye on the DEF tank level is if there is a draconian way to make them pay attention.

jtk

You’re not wrong, and that’s most likely why the system is put in to place, it just makes no sense to me. But the point is moot, it’s here to stay and no ones changing it because I’m complaining about it.

[Bill Dufour]

I understand it has a sensor so it will shut down if you fill with just plan water instead of DEF.
Bill D

[Rob Luter]

Mine would smell. Def’d mine smelled like ammonia. While Smells are subjective, for short idling like if I were hooking up a trailer- I still prefer diesel fuel exhaust to a def exhaust. It would make me nauseous if I had to smell it longer than a min or so.


You’re not wrong, and that’s most likely why the system is put in to place, it just makes no sense to me. But the point is moot, it’s here to stay and no ones changing it because I’m complaining about it.

Let me elaborate. No diesel odor. Mild chlorine odor to my nose. I can start it in the garage (with the door open) prior to my wife coming out and after 5 or 10 minutes she still can’t smell a thing.

[Jim Koepke]

Some diesel trucks are equipped with remote start so the vehicle can warm up while pouring a coffee for the road.

jtk

[Jeff Bartley]

It is just a Urea solution in deionized water. The standard specifies the concentration at 32% (I think it is specified w/w (mass/mass) rather than vol/vol or even the abomination of w/v)
Personally, I would have rather have the newer system on my truck, since the non-DEF trucks have issues with soot buildup in the EGR system (at least a certain range of Ram Cummins). It is less of an issue if the truck is always run hard...

Also, with DEF you can get a more efficient tune. My father-in-law has a five year newer RAM than mine (I am on the hand-me-down trail :-) ) and he gets much better fuel efficiency.

What kind of mileage do the new Cummins get? Just curious, I still see 21 mpg from my ‘96 12-valve.

[Jeff Bartley]

It is just a Urea solution in deionized water. The standard specifies the concentration at 32% (I think it is specified w/w (mass/mass) rather than vol/vol or even the abomination of w/v)
Personally, I would have rather have the newer system on my truck, since the non-DEF trucks have issues with soot buildup in the EGR system (at least a certain range of Ram Cummins). It is less of an issue if the truck is always run hard...

Also, with DEF you can get a more efficient tune. My father-in-law has a five year newer RAM than mine (I am on the hand-me-down trail :-) ) and he gets much better fuel efficiency.

When I got my diesel sedan I was a bit miffed at the DEF issues too. Mine will actually shut the car off if you run dry. You get a warning light about 1000 miles in advance. That said, a tank lasts about 10K miles and it's easy to just top it off when changing the oil. The stuff is cheap and easy to add. I like that it takes NOx out of the exhaust. I like that my exhaust has no odor. My car gets 40 MPG in mixed driving and 50 MPG on the freeway. A 15 gallon tank of fuel will last 600 miles daily driving and 700 miles on a trip. Lots more upside to downside. What chaps my hide is that they (BMW, VW, Benz) are not bringing diesels into the US any more. This whole VW fiasco and the decision that electric cars are the future has made them unavailable unless you want to buy a massive pickup.

I’m in the same camp Rob, with the addition of Def systems diesels are no longer emitting the Nox, they get fantastic mileage, fuel is cheaper to refine.....what’s no to love? Add to that low end torque for days? So fun to drive, esp with a third pedal! But so few have experienced that joy. I may just try to find an older TDI to play around with.