> It's weird, VW say that if your car if affected, they'll fix it. It's a software update that a) won't affect performance and b) won't affect fuel consumption. So, why did they do it in the first place?

I think it's safe to say that until someone actually has had their car fixed by this new software, and then tested its performance and consumption after that we can assume that it's impossible. I'll believe it's possible when I see it.

My guess: VW europe will claim to make a performance-neutral fix, but simply cut the performance and increase the consumption of the affected cars. Anyone in the EU who finds that annoying can try to scream with very little chance of getting any compensation from VW because of how EU consumer laws work.

In the US where they are actually scared of being sued into compensating customers they will make more advanced fixes potentially even retrofitting urea systems where possible.

> In the US where they are actually scared of being sued into compensating customers they will make more advanced fixes potentially even retrofitting urea systems where possible.

You don't think there will be class action lawsuits if they mount a diesel exhaust fluid (DEF) tank taking up any cargo or other usable space? Or if they don't provide a lifetime supply of free DEF (or more likely a cash payment to cover the likely DEF costs for the projected life of the car)?

As an EU consumer I'd be delighted if they did that, even if I was paying for my own DEF and it took a chunk of my cargo space. I'm sure there will be class action lawsuits in both the US and the EU regardless.

The reason they are only doing the cheap software changes in the EU is likely because they think they will either win any legal processes OR it's much cheaper to lose them than to fix cars (both of which are probably true).

> As an EU consumer I'd be delighted if they did that, even if I was paying for my own DEF and it took a chunk of my cargo space.

That's very personal thing and it's easy for a lawyer to argue that VW has no longer delivered a car conforming to the original specifications for cargo space/capacity, etc and that the consumer is due compensation to compel them to accept the new specifications. I can't imagine that flying without additional compensation in the US (and frankly, don't believe that it should).

I completely agree - however as an EU '09 Audi owner I have zero hope of getting anything other than a car with 10-20 less horsepower that does a few less mpg than before the fix. This in turn also means that its resale value drops around $1k or thereabouts (hard to tell). In any case, I have zero hope of getting a single penny from VW because the car no longer meets my expectations. That is even if I participate in some class action process. I'd be shocked to even get a 5% rebate on new car.

Interesting. VW is offering TDI owners in the US a $500 Visa prepaid card, a $500 VW dealership card, and to receive, you don't need to release VW from any other claims or liability.

https://www.vwdieselinfo.com/updates/letter-to-2-0l-tdi-owne...

Set aside the VW dealership card, you'd still be getting $500 as an affected US owner. Seems odd that EU (which I find generally more consumer-friendly than the US) would be less generous. (I'm not doubting you; it just mismatches my normal expectations.)

I think one difference is that VW wants to break into the US markets, but is already a dominating brand in the EU market. The number of diesels sold in the US (low) compared to the risk of legal fallout there (high) means they have one strategy there, compared to the EU where the number of diesels sold is much bigger. If VW offer compensation without requiring you to not claim anything in the future - that's pure goodwill/marketing. That's good to hear. They probably can't afford that here, or they don't want/need to because of the market situation.

Thank you for mentioning this.

I am a owner of an affected TDI but did not receive the letter (or threw it away mistaking it for another car warranty junk mail letter) and was unaware of the "TDI Goodwill package"

Did you buy or lease it new from the dealership?

Any time I go in for service they ask if I've registered for the package yet and bug me to do so (presumably so I get the dealership card and they know I'll be back).

You didn't need to buy it new from a dealership to get the package.

I bought mine used from a 3rd party dealership (non-VW specific), and still got the goodwill package.

Sign up for it here: https://www.vwdieselinfo.com/goodwill_package/

I bought it used with 80,000 miles on it. Second owner.

I'm a big do-it-yourselfer and generally avoid dealerships.

BTW If you haven't changed your serpentine belt lately, do it! Mine broke at 90,000 miles, wrapped itself around the timing sprocket, cause the engine to jump timing and broke 7 valves. Cost me about $3500 for a new head. Apparently it's fairly common.

That would be timing belt, not serpentine belt, I think. (Just in case someone wants to go looking through service records or talk to a service advisor about the job.)

Nope, it actually was the serpentine belt. The serpentine belt shredded, wrapped around the crankshaft and worked its way into the timing cover, caused the timing belt to slip, which, since this is an interference motor, was disastrous for the valves.

Forum threads:

https://forums.tdiclub.com/showthread.php?t=424956

https://forums.tdiclub.com/showthread.php?t=407745

There is a design flaw that allows a shredded serpentine belt to work it's way past the timing cover and wreak havok. When I took apart the engine, the timing belt was in-tact.

There is now available a guard that you place behind the main crankshaft pulley to stop this from happening but I can't find it right this second.

What the software actually did was stop the mixing of DEF[0] into the exhaust gases. DEF is a consumable catalyst that reduces NOx emissions[1]. If they had mixed it in properly as they did when the car was under test, then fuel consumption or performance would not change, but the resovwair of DEF inside the car would be depleted more quickly.

My theory is that they reduced the consumption rate of DEF so that it could be filled up during regular services without being depleted before one was due. They could instead just provide a larger reservoir of DEF, or schedule more frequent maintenance. Either solution would not impact fuel consumption or performance but would fix the issue. Remember DEF is injected into the exhaust gases and does not interact with the engine at all.

[0] https://en.wikipedia.org/wiki/Diesel_exhaust_fluid [1] https://lwn.net/Articles/670488/

The models affected by this do not use DEF[1]

I used to understand the system fully but have lost some of that as it's no longer important to me. In short, the CBEA engine line has a complex emissions control system consisting of 3 separate catalytic converters that each must be regenerated from time to time, and two exhaust gas recirculation systems. These regeneration cycles reduce performance and increase fuel consumption.

For example, a DPF regeneration cycle closes a valve in the exhaust which increases system pressure and thus system temperature, while also triggering a post-combustion fuel injection -- injects unburned fuel into the cylinder on the exhaust storke -- to increase the exhaust temperature to burn off soot that accumulates in the particulate filter.

It is likely a change in the schedule of these regeneration events that is necessary to bring the vehicle into compliance.

There is a long PDF[2] that goes into detail how the emissions systems work on these cars.

[1] http://www.myturbodiesel.com/images/dpf3.jpg

[2] http://www.natef.org/natef/media/natefmedia/vw%20files/2-0-t...

> The models affected by this do not use DEF[1]

Huh? Some certainly don't, but 2014 TDI Passats like mine use DEF. My reservoir currently lasts about 10000 miles, which is also the manufacturer's service interval.

Oops...my apologies.

I was not aware that both versions were affected -- looks like this information came out a bit later. I'll edit the original post.

Edit: Or not...looks like too much time has passed.

Maybe that's the case for engines that use DEF, but the cheating was done in engines with no DEF injection systems too.

In those engines at least I doubt very much "the fix will not affect the performance or fuel economy", unless they resort to extremely expensive changes that seem unlikely (like adding said system to cars that don't have it).

So they'd be dumb to say it just for PR reasons - A bunch of people will test it, if their statements turn out to be false, they'll be a massive class action suit that will be pretty easily won.

It's entirely possible, of course, that they are counting on this, and decided by then things will have died down enough PR wise that making the PR statement makes sense.

I am not sure, I have no idea what they did in cars that didn't have the urea injection system.

My car is affected by this recall (as confirmed by a letter from the VW group to my registered address) and does not have a DEF / AdBlue system.

That's applicable to engines featuring DEF, but for the rest my theory is that they will just increase EGR to lower combustion peak temperature and thus decrease NOx at the cost of engine efficiency. There's no magical software fix that can decrease NOx without affecting the combustion and thus either performance or efficiency. That would be the holy grail of thermal engine research!

*reservoir, but I enjoyed your spelling of it anyway.

My understanding, having owned two TDI vehicles affected by the recall, is that the statement of not affecting performance and fuel economy is based on the fact the EPA numbers were calculated with all the emissions systems active.

Now what will be affected are all those individual reports of ten to twenty percent better than EPA numbers many TDI fans love to rave about. Both my TDIs were like 40 highway / 30 city rated and yet over their lifetime the vehicle average was closer to if not higher than the highway number. Granted I do not drive like most people I see; racing to each stop and such. Still the numbers I had versus what the EPA said cannot all be explained by good driving.

My question is, if it was so easy to slip diesels past emissions testing then how about gasoline powered cars? Worse with the regards to diesels I think a truck manufacturer was caught cooking numbers in the nineties?

Yes, Caterpillar.

http://jalopnik.com/how-the-epa-won-1-billion-from-diesel-ch...

More information there, DEFCON talk of someone reverse engineering the ECU and then discovering the actual data that corresponded to the EURO5 emissions test : https://www.youtube.com/watch?v=xZSU1FPDiao

Not DEFCON, CCC.

They have their own video streaming service which doesn't do the tracking Youtube does:

https://media.ccc.de/v/32c3-7331-the_exhaust_emissions_scand...

So the disassembling confirms that ECU is just not feeding the exhaust with AdBlue/Urea. So what is the advantage for VW in all this?! It does not make your car more powerful, it makes it less eco-friendly, you are just saving money on AdBlue/Urea.

They could easily reverse it back, the power will be the same, pollution levels will be okay, only AdBlue/Urea consumption will increase.

I've read that US regulations required no additives outside of regular service intervals.

Assuming that both of those claims are correct, my guess is that they did it to make their cars more affordable in EU where road tax is related to emissions. Although I personally don’t know anyone who bought a VW because the yearly traffic fee is lower than in other cars. Generally speaking their cars are stellar in every account which makes this whole situation seem utterly stupid. They didn’t need to do it, they already had the advantage towards the competition.

That is likely a large part of it at least (reaching 120g/km in consumption is very important).

BUT the CO2 emissions is proportional to the fuel consumption. There is (very simplified) only one way to get both better performance and lower consumption from an internal compbustion engine, and that is to increase the temperature of the combustion. This gives higher power output and lower consumption and thus lower CO2 emission.

For diesel engines increasing temperature has the drawback of producing NOx emissions. In order to reduce NOx emissions, the combustion must be cooler/fatter so uses more fuel and/or provides less power. The hack that VW did was to use a profile for the fuel mixture that produces low NOx and low power when it detects that it is being measured. Otherwise it produces high power, and low consumption.

Using the cooler/fatter fuel mixing is a simple way of cutting NOx, but it also gives worse fuel consumption and power. For engines without urea devices, there is (as far as I can see) no possible workaround. They will have to either make hardware changes to the cars or make a software fix that reduces performance and increases consumption.

VW is not in the same situation in the U.S. though. They have a lot of competition (they're not even in the top 10), so if they didn't do it in the the EU, but cheated on the U.S. models, there would be vastly differing output levels, signaling a discrepancy between the two models.

Company cars (which are tax-exempt or partially tax-exempt in some parts of Europe) care a lot about this.

The software before the update was used to detect if a car was being tested for emissions/ fuel consumption. Then it lowered power and fuel consumption. So it gave skewed figures. Which means in normal driving it was always giving more than advertised figures. So the fuel consumption has not changed from before update for normal driving. So you won't see any difference.

Edit: ah my bad. Ah, it specifically relates to particulate emissions, that is not related to fuel consumption

> So the fuel consumption has not changed from before update for normal driving. So you won't see any difference.

Uh, I think you've got it backwards. Won't the updates mean it drives in 'test mode' (e.g. acceptable emissions that meet the standards) all the time? Meaning that it will result in some downside (which was apparently bad enough that they cheated in the first place)

Specifically, reducing NOx (without using DEF) pretty much requires the engine to burn a richer mixture. This means more fuel injected, so less fuel efficiency and more unburnt hydrocarbons clogging up the particulate filter. Without retrofitting DEF systems onto the older cars, any fix is likely to be a significant hit to efficiency and reliability. I think maybe performance would suffer too but I forget how that would work.

But then how will they pass the test?

It will still pass, they were just pushing the emissions tests lower so that the car could fit in a lower tax bracket. I don't know about every country, but in the UK you get taxed on how polluting your car is.

I believe that various governments have made a promise not to increase the taxes on existing cars, as the consumers were unaware at the time of purchase.

Is VW paying the tax difference, or walking away with a government handout?

No it's the consumers being taxed on road vehicles every year. The lower tax makes them quite attractive in comparison to other manufacturers.

What would be the point of getting your car fixed, assuming you're describing it accurately?

Getting owners to go in for the fix is part of the problem. Some states will most likely require it to be done before renewing the license plate, or before allowing resale, etc.

It'll definitely impact performance.