What is AdBlue

[tlouis1947]

I saw that AdBlue when I ran down to 3/4 tank of gas.

[Road Explorer]

It's just a brand name for DEF. Most newer diesel engines have to use DEF (a mix of demin water and urea) with an SCR to reduce emissions.

I can't remember when that basically became the standard (law?) in most places, but my mid-2000s diesel pusher didn't need it.

[AyMazingATS]

AdBlue, as it is called in Europe is DEF here, aka Diesel Exhaust Fluid.

It is an emissions control liquid that is required by modern diesel engines.

It is injected into exhaust stream to eliminate harmful toxins. Much the same way a catalytic converter works on a car.

[gallagher4005]

My CR England truck had the DEF fluid.
Filled it up every other tank of fuel.
I also got 9mpg out of it!

[cube]

AdBlue is a brand of DEF (Diesel Exhaust Fluid) which is an emissions controlling device put in place for diesel vehicles 2007 and newer. A DEF system is commonly paired with a DPF and EGR systems. DPF (Diesel Particulate Filter) is like a catalytic converter for big trucks, capturing what the EPA deems as harmful to the environment such as PM (Particulate Matter AKA black smoke) and NOx (Nitrous Oxide). DPF and DEF work together as DEF is sprayed after the exhaust has passed through the EGR (Exhaust gas recirculation) and DPF systems to reduce the PM and NOx levels. DPF is also known as Selective Catalytic Reduction or SCR. If you want to know if a truck has a SCR exhaust, the truck wont have exhaust stacks (2007 and newer) at least on PACCAR products (Kenworth, Peterbilt and DAF). Some 3/4 tonne, 1 tonne, 2 tonne and 5 tonne trucks will have EGR's, DPF and DEF.

[TheGamerHd]

Man u should see how much cash I have like billions and bunch of warehouses and trucks

[room217au]

Originally posted by Chump Car:

DPF and DEF work together as DEF is sprayed after the exhaust has passed through the EGR (Exhaust gas recirculation) and DPF systems to reduce the PM and NOx levels. DPF is also known as Selective Catalytic Reduction or SCR. If you want to know if a truck has a SCR exhaust, the truck wont have exhaust stacks (2007 and newer) at least on PACCAR products (Kenworth, Peterbilt and DAF). Some 3/4 tonne, 1 tonne, 2 tonne and 5 tonne trucks will have EGR's, DPF and DEF.

Interesting. Never seen a DPF-fitted truck than needed DEF. The Diesel Particulate Filter does exactly that. They are self-cleaning in 'auto' mode.
In a late model Mercedes 'Sprinter', the DPF to replace new, is $7000. An actual quote from Merc dealer here in Australia. When it starts failing, the vehicle goes into 'limp' mode (limited acceleration, limited top speed). You can have them cleaned (around $400) but they'll never last as long again as the original and will always require regular cleaning.

[Hiro Protagonist]

Originally posted by room217au:

Interesting. Never seen a DPF-fitted truck than needed DEF. The Diesel Particulate Filter does exactly that. They are self-cleaning in 'auto' mode.

The DEF system isn't for regenerating the DPF, it is for NOx reduction (the DPF is for particulates) - they are complimentary systems. Although ironically the need for DEFs is partly due to the shift towards lean-burn diesels to reduce particulates, which increased NOx emissions. The units can be combined however, but are two different systems doing two different jobs - DPF is a physical filtering process, DEF/SCR a catalytic reaction.

[Wolfgang]

Also some info about it here:
https://en.wikipedia.org/wiki/Diesel_exhaust_fluid

[tlouis1947]

Thank everyone who replied. I have a better feel for what AdBlue is. Thanks

[room217au]

Originally posted by Hiro Protagonist:

The DEF system isn't for regenerating the DPF, it is for NOx reduction (the DPF is for particulates) - they are complimentary systems. Although ironically the need for DEFs is partly due to the shift towards lean-burn diesels to reduce particulates, which increased NOx emissions. The units can be combined however, but are two different systems doing two different jobs - DPF is a physical filtering process, DEF/SCR a catalytic reaction.

My point was that the Diesel Particulate Filter (the catalytic converter kind, found in most mid-sized trucks at least in my country) does not need fluid sprayed into the exhaust stream, as intimated by user Chump Car earlier in this discussion.

[Hiro Protagonist]

Originally posted by room217au:

Originally posted by Hiro Protagonist:

The DEF system isn't for regenerating the DPF, it is for NOx reduction (the DPF is for particulates) - they are complimentary systems. Although ironically the need for DEFs is partly due to the shift towards lean-burn diesels to reduce particulates, which increased NOx emissions. The units can be combined however, but are two different systems doing two different jobs - DPF is a physical filtering process, DEF/SCR a catalytic reaction.

My point was that the Diesel Particulate Filter (the catalytic converter kind, found in most mid-sized trucks at least in my country) does not need fluid sprayed into the exhaust stream, as intimated by user Chump Car earlier in this discussion.

I think Chump Car was getting his acronyms mixed up which created most of the confusion - no DPF I know of uses Adblue/urea to initiate the regeneration cycle, they either burn off the accumulated soot during normal driving if the conditions are right, or inject extra fuel (like anti-lag/afterburner) to heat up the exhaust (which needs to be done manually every so often if the normal driving conditions aren't met, this is what causes a lot of failures of DPFs on passenger cars that only get driven short distances)

[room217au]

Originally posted by Hiro Protagonist:

..which needs to be done manually every so often if the normal driving conditions aren't met, this is what causes a lot of failures of DPFs on passenger cars that only get driven short distances)

I don't know about cars, but all the trucks I've driven have two modes for DPF. You can leave it on 'auto' and the DPF cleans itself, while driving the vehicle normally, when the filter is 'full'. This mode is always set for rental vehicles.
Or you can set it on manual and you need to pull over when the DPF readout says you need to and you idle the engine for 20mins.
All heavy trucks (semi trailers) here are fitted with the DEF system.