OT Discussion on VW

David G

Well-known Member
The reports I have read on VW indicate that they got caught on NOx emissions. My understanding is that NOx is controlled by EGR, DEF catalyst, or a combination of both. I have DEF on my truck, it gives me better performance and mileage due to the reduced EGR requirements. I also assume it costs quite a bit more money to implement, thus VW probably decided not to spend the money.

Does the VW system use DEF?

Do you know of other systems out that do not?

Thanks
 
am I correct that the car detected it was being tested therefore it altered the "tune" to pass the test,then when the test was completed the car altered the tune again to a non compliant reading.
 
Makes me wonder what other things manufacturers have loaded in to vehicle computers to get you in for unnecessary repairs.
Frank
 
Thing is they could have passed on the cost of adding the DEF system like everyone else did and not taken the risk of being caught. Leave it to German ingenuity to cheat the system. I love it EPA didn't have a clue of the whole scheme and it took some computer geeks in a abundant collage to discover it. To bad it may cost them the company.
 
Yes. And I always wondered about why the EPA tests emissions by Parts Per Million.

What VW did was make the engine run far less efficiently so it could pass the PPM test, then set it back so the car got good fuel economy and horsepower. What I haven't seen is whether the car gets better emissions per mile driven with the cheated setting.
 
NOx, which is comprised of NO and NO2, is a product of high combustion temperatures. It was not an issue until the 60s saw high compression. They reduced it in the 70s with lower compression and EGR. The computer came along in the 80s, so it helped allow the compression to come back up, and so the mileage/performance did also. I do not think that Diesels had to comply with NOx emissions until about the last ten years. We saw performance/mileage decrease until the advent of DEF, which allowed higher efficiencies because the NOx was knocked down in a catalytic converter instead of doing it in the combustion chamber. I have had DEF in my latest truck, which is 5 years old, and 120K, zero issues with it.

I am not aware of which engines have DEF and which do not, so assuming VW did not to cut costs, also not familiar with the years of the issue. It is NOT fair to the owners to detune the engines now and have them live without compensation for it, but class actions only make the lawyers rich, what a mess.

I bet someone here knows the answer on DEF and the years it was used.

My industrial customers also have to conform to NOx emmisions on generation, burners and boilers. Some are using EGR, some are using DEF. I am seeing more EGR right now, because natural gas is so cheap, but I bet that would change if the price of fuel comes up.
 
No. The VW diesel automobiles sold in the US do not use DEF and show sigificantly higher EPA mileage figures on the window sticker than do competitive models from other manufacturers which do use DEF.

Fact is, there is no free lunch regarding the nonsensical EPA regulations and VW has been caught cheating resulting in huge marketing advantages vis a vis other manufacturers.

It will be interesting to see how the dust settles on this issue.

Of course, the federales are interested mostly in revenue from the enormous fines that VW will be forced to pay in order to continue selling vehicles in the US.

Dean
 
In another VW discussion on another site, an owner said that certain models of 14 and 15 TDI have DEF, but not all.
 
(quoted from post at 10:38:32 09/27/15) The reports I have read on VW indicate that they got caught on NOx emissions. My understanding is that NOx is controlled by EGR, DEF catalyst, or a combination of both. I have DEF on my truck, it gives me better performance and mileage due to the reduced EGR requirements. I also assume it costs quite a bit more money to implement, thus VW probably decided not to spend the money.

Does the VW system use DEF?

Do you know of other systems out that do not?

Thanks

The Jetta uses EGR for NOx and DPF for particulates. While the Passat utilizes a DEF+SCR solution.

There are more than a couple knobs to adjust on engine management that affect the exhaust.
In general high combustion temps generate greater amounts of NOx. By adding EGR at a higher percentage you limit the amount of O2 in the cylinder leaning out the mixture further and dropping combustion temperature, this increases particulates though. You can raise injection pressure to get better atomization and better burn but at the expense of NOx. You can add multiple injection shots (pre/main/post typically but from what I understand Bosch could run up to 5 injection events on a cycle). You can stage turbos for better transient response to control primarily particulates. You can do a lot of the same with variable geometry turbos. Deere was able to get this to work but Cat fell short on reliability.

There are so many adjustments to be made with trade offs that negatively affect something else. The software to run a modern engine is incredibly complex.

The EPA tests on a canned cycle on a dyno so everyone is on a level playing field. VW engineers wrote code into the engine ECM to detect the EPA test cycle and would then run the engine in "clean" mode until the test was over.

http://www.theicct.org/real-world-exhaust-emissions-modern-diesel-cars
 
I have a 2012 TDI wagon. I have kept detailed records of mileage for 160,000kms and it averages 5.8L/100km, that's over 40mpg US.

Regardless of the EPA rating, I bet the VW is less harmful to the environment than my 6L gas Chev Truck, that gets a little over 12mpg.

If VW wants me to bring my car in to have it retrofitted back to meet EPA, I won't do it if its just going to ruin my fuel mileage. It's a lot cheaper to drive the car than my truck. I cringe every time I turn the key on the truck... Here in Canada we're paying 1.239/L (that's $3.51USD/US gal). At 12mpg that adds up fast.

If the VW burns less fuel, its probably also easier on the environment.

Bye for now,

Troy
 
It basically boils down to the EPA does not want diesel vehicles. VW played the game and lost, which now gives more ammunition to the EPA to further lean on diesel powered vehicles.
Sad thing is some kid driving a hopped up diesel pickup with a tuner and stacks probably puts out more emissions and particulate matter than a whole fleet of VW's
 
(quoted from post at 12:09:37 09/27/15) I have a 2012 TDI wagon. I have kept detailed records of mileage for 160,000kms and it averages 5.8L/100km, that's over 40mpg US.

Regardless of the EPA rating, I bet the VW is less harmful to the environment than my 6L gas Chev Truck, that gets a little over 12mpg.

If VW wants me to bring my car in to have it retrofitted back to meet EPA, I won't do it if its just going to ruin my fuel mileage. It's a lot cheaper to drive the car than my truck. I cringe every time I turn the key on the truck... Here in Canada we're paying 1.239/L (that's $3.51USD/US gal). At 12mpg that adds up fast.

If the VW burns less fuel, its probably also easier on the environment.

Bye for now,

Troy

Troy, I am 100% in agreement with your statement. It is impossible to reduce emissions without also reducing fuel mileage. The auto, truck, and tractor manufacturers need to join forces and tell the EPA to take a hike.
 
The auto industry makes up 1/7 of the German economy. Some are worrying what the VW screw up might do to the German economy. 11 Million cars is a lot of cars to recall or replace.

If a computer program can make the engine run clean while testing, why can't the problem be fixed with changing the computer program?
 
(quoted from post at 15:25:09 09/27/15) The auto industry makes up 1/7 of the German economy. Some are worrying what the VW screw up might do to the German economy. 11 Million cars is a lot of cars to recall or replace.

If a computer program can make the engine run clean while testing, why can't the problem be fixed with changing the computer program?

It can. You'll lose the "fun" factor especially in the Jetta without DEF.
 
My understanding is DEF is only required in Ca. I know of 4 Peterbilts here that Pete or Cat could not make run. Less than 2000 miles. Cost 8000 dollars per truck to take the Def system off and change the computer. Friend has a Dodge with a Cummins the same way. Think h
his was $5000 to change.

The DEF system has only just begun to have problems show up. Talk about big bucks!!
 
The computer could easily be programmed to be in the "clean mode" all the time but then the power, responsiveness, and economy would suffer. This would leave customers dissatisfied since these are probably the reasons they bought the diesel in the first place.
 
The big problem for VW will be after they recall the cars, and then the mileage drops by 10 MPG. Buy one now, and never take it to the dealer again.
 

I would like to see the owners to tell the EPA were they can shove it... I own it you passed it I am going to drive it and enjoy it... This is noting new manufacturers have been able to resolve emission issues for years with EPA approved updates, updates that would have never passed from the get go...
 
You'll have to buy one from a private seller if you want to buy one now. They were ordered not to sale any more of them, new or used. The problem with never wanting to take it to the dealer is that any time you have exhaust system issues,you will have to take it to a repair shop that knows a thing or two about them but is not a dealer.
 
>The VW diesel automobiles sold in the US do not use DEF and show sigificantly higher EPA mileage figures on the window sticker than do competitive models from other manufacturers which do use DEF.

Bear in mind that the EPA mileage is calculated as part of the same tests as the emissions. So it's reasonable to assume VW's EPA mileage ratings are just as bogus as their EPA emissions ratings.
 
>If a computer program can make the engine run clean while testing, why can't the problem be fixed with changing the computer program?

1. Customers are not going to be happy to find that their reprogrammed VWs are sluggish and ill-tempered when they run a map that will meet EPA requirements under real-world conditions.
2. Without adding DEF, it's unlikely VW can meet the NOx requirements and still have cars you would want to drive.
 
It is likely that the cars in question used Exhaust Gas Recirculation (EGR) and not DEF. DEF is after treatment and does not affect the engines performance. It is the technology that seems to work and all new diesel use it. Trying to get the NOx down in cylinder would be the source of the problem. When they did that the cars would likely be barely drive able as Navistar found out in trucks. They used EGR and the competition used DEF and the competition won. New Navistar engines use DEF as a result. Cat did not develop DEF technology and now no longer produce truck engines.
 
(quoted from post at 21:57:13 09/27/15) Cat did not develop DEF technology and now no longer produce truck engines.

Cat got out of the on-highway truck engine business after the 07 model year T4a debacle with their CGI and CRS failure. CGI is Clean Gas Induction and used exhaust from downstream of particulate filter to pump back into intake the thought being that removing soot would increase top end engine life. CRS is the regeneration system for the DPF that injects fuel and clean air into the exhaust before the DPF to burn the soot out of the DPF brick and reduce it to ash. This is where a lot of your fuel economy is lost on T4 engines, a lot of fuel is burned to regen. The CRS system was a reliability problem on 07 Cat truck engines and left a sore spot for customers, management decided to abandon truck engines and focus on off-highway for machinery.
 
Actually Volkswagen used DEF (they call it AdBlue) on their bigger diesels like the Passat and Touareg. They had the same "program" to bypass most emissions when not being tested. I recall one owner commenting on why he could go twice or three times as long as his manual said without adding any.
 
Wish I had bookmarked it but an article I read said that the VW's would most likely have passed emissions testing without the cheat code programed in.

Rick
 
(quoted from post at 14:49:31 09/27/15)
Sad thing is some kid driving a hopped up diesel pickup with a tuner and stacks probably puts out more emissions and particulate matter than a whole fleet of VW's

I've seen ""grown adults"" driving diesel powered pickups with a super power chip blowing BLACK SMOKE also.
 
My understanding is that the effected cars did not use DEF/ADBlue. Only the larger models like the Passat and Toureg used DEF, hence why they are not effected by the recall as far as I know.
I also noticed when the emissions crap came out several years ago that VW dropped their mileage claims by 15% or so... and now in the last couple years those claims have increased again... Looking back it's probably no big surprise why they altered the programming. Better performance, better economy. LOL. This is kind of one of those moments where I want to go out and buy a VW.

Rod
 
(quoted from post at 10:38:32 09/27/15) The reports I have read on VW indicate that they got caught on NOx emissions. My understanding is that NOx is controlled by EGR, DEF catalyst, or a combination of both. I have DEF on my truck, it gives me better performance and mileage due to the reduced EGR requirements. I also assume it costs quite a bit more money to implement, thus VW probably decided not to spend the money.

Does the VW system use DEF?

Do you know of other systems out that do not?

Thanks

Yes my 2015 Jetta diesel uses DEF as do the Passat and GOLF Diesels.
 
Mark, I'm not a diesel owner, so can DEF be blended in the fuel like mixing oil with gas for 2 cycles or does it require some type of injection?

VW will have to come up with some kind of fix, 11 million cars is a ton of money.
 
(quoted from post at 12:03:19 09/28/15) Mark, I'm not a diesel owner, so can DEF be blended in the fuel like mixing oil with gas for 2 cycles or does it require some type of injection?

VW will have to come up with some kind of fix, 11 million cars is a ton of money.

It gets injected into the exhaust before the SCR (selective catalytic reduction) to turn the NOx into N2 and H20. Some other chemistry going on in there too.
 

Shut off the EGR and advanced the injection event back up to obtain peak average cylinder pressure during the combustion cycle.
No different than the gains diesel tuners obtain at stock fuel settings.
Intercoolers also reduce NOX
 
(quoted from post at 12:33:56 09/27/15) Thing is they could have passed on the cost of adding the DEF system like everyone else did and not taken the risk of being caught. Leave it to German ingenuity to cheat the system. I love it EPA didn't have a clue of the whole scheme and it took some computer geeks in a abundant collage to discover it. To bad it may cost them the company.

Every employee of EPA should be dragged to a trench in the back 80 and dealt with there.
 
Any of you guys ever watch any kind of jet take off?How bout a diesel rig?Or an oil burner ship at sea?But its our cars causing the greenhouse gases. Hoss
 
They will try to do a software-only fix, because that's the cheapest and easiest solution. But that's not going to satisfy the EPA and FTC, let alone the various class action lawsuits. So they'll be forced to do one of the following:
1. Retrofit the offending models with DEF.
2. Do the software recall and give every owner a check to compensate them for cars that are less than what the customers thought they were buying.
3. Buy every single car back.
 
>But its our cars causing the greenhouse gases

Well, in the case of half a million VWs sold in the US plus a few million in Europe, that is exactly the case. 20-40 times the allowable NOx.
 

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