Not being rude, but I'm having trouble parsing that part of your comment.
Do you mean that the US authorities won't let diesel car owners re-fill the diesel exhaust fluid tank by themselves, i.e. the re-fill must be performed by a dealer?
Also is the DEF tank just a US thing? I'd never heard it before (UK resident here).
When the sales guy told me the tank only had to be filled at service intervals, it sounded strange. People on the TDI forums thought it was just because VW didn't want to scare away customers with an extra thing to do, but you can buy the stuff at any gas station and pouring it into the tank is not difficult.
When the scandal broke the assumption was that they mistuned the DEF cars out of arrogance, and again to avoid spooking customers with extra maintenance.
Now it sounds much more like they tuned it that way because this regulation would have crippled the car with an enormous DEF tank otherwise. It is possible that such a regulation combined with a 10,000 mile service interval only makes engineering sense on mid-size trucks or larger.
This doesn't have anything to do with them failing to build a working LNT solution and cheating with those previously, of course.
If you think that's a problem, then please explain why this isn't also a problem for the gas tank. I don't know of any cars which will continue to drive (but spewing extra toxins) when the gas or diesel tank is empty.
Customers don't seem to have much of a problem topping up their diesel tank every week or two....
And actually I'm not so quick to assume this is only a stupid decision either. Hanlon's razor still applies but there is also a distinct possibility that this regulation was "encouraged" as a play to make small diesel cars less competitive.
VW doesn't want their cars going into limp mode. They don't want customers calling up asking why their car is acting funny. They don't want to increase the maintenance load on their customers. They don't want customers coming in for unnecessary service appointments (especially for stuff they wouldn't be able to charge for). Making a tank big enough to last as long as the motor oil seems like an easy, low tech solution. Sometimes simple is better.
After hearing about this regulation it seems an obvious reason why they would keep the cheat enabled even after adding a DEF system.
It is feasible and they already do it.
Or do you mean the Chevy Cruze? They must have some strategy that works (so far).
Some of the VWs are getting bigger DEF tanks. For the cars that this isn't an option, I don't think VW has said exactly what they are going to do. They could just disable the cheating mode on the software. Fuel economy and performance would suck, but the emissions would be at acceptable levels.
There's been a lot of speculation all along, will they retrofit DEF systems, will the cars just get super unreliable because the systems can't handle prolonged legal operation, etc.
2013-2014 cars need to hold 1/2 gallon more exhaust fluid and apparently that's doable (and also new firmware).
Older cars are a bigger problem and will likely get a combination of fixes but in the end, they are going to be louder, fuel hungry cars after getting "fixed".
The oldest cars will likely get owners a buy-back offer because the depreciated value is lower than the cost to fix.
And what exactly will this firmware tweak do? If it decreases performance or fuel economy, then that isn't acceptable. The customer bought the car because it advertised X horsepower and Y mpg; if the firmware tweak changes that, then that's false advertising and the company needs to refund their money in full.
What's really stupid is that it sounds like they should be able to get the advertised power and economy with the required low emissions simply by using more DEF. I'm assuming the DEF liquid isn't too expensive here, but if they just made it so you needed to refill it every 1000 miles, that should solve the problem. Heck, why can't they just make it available at gas stations too?
Having this idiotic notion that only dealers should be able to refill the stuff, and that it needs to be done at 10k intervals, is what's making it impossible.
Why not require that cars must be able to carry enough fuel to drive 10,000 miles while they're at it? It makes as much sense.
[0]https://www3.epa.gov/otaq/documents/nonroad/420f14017.pdf
But yes, the issue is that the US requires dealers to refill them. And also sets a limit for how often refill cycles may happen. And the weight of the tank sets a limit on how large it may be.
The result is simple: Small Diesel cars can’t exist legally in the US.
[0]: https://en.wikipedia.org/wiki/European_emission_standards#Em...
And that is, of course, intentional. To keep some of the foreign competition away.
Aside from trucks, that is.
I tend to keep up on cars, and I can't name any American-brand, small diesel off the top of my head from the last 30+ years, aside from last year's Chevy Cruze.
Edit/clarification: I'm speaking strictly of the American market. If American companies make small diesel cars for international markets, it's not at all relevant to discussing small diesel cars in the US.
GM don't sell Opels in the US, although they could re-badge them as Chevrolets.
I disagree, certainly from a UK perspective.
Most modern Ford diesel engines are the product of the collaboration between Ford, Citreon and Peugeot [0][1].
Ford diesel Focus and Mondeo's are hugely popular and are quite reliable, reasonably sporty and fuel efficient things. My dad's last three Fords (Focus, Mondeo then Focus) were all diesels and he loved them. Virtually everyone I know that own's a Focus has one of the diesel versions.
To the extent that consumers remember crappy American diesels, I would say the most infamous is the Olds diesel. GM took a (not so great) SI engine and turned it into a CI engine.
American companies make some diesel cars in other markets (Ford, and GM with its Opel and Vauxhall brands) but they have a significantly smaller market share in diesels than in gasoline engines.
Easiest way to look at it is this: http://www.statista.com/statistics/425324/eu-car-sales-share...
You'll find Opel, Vauxhall and Ford towards the lower end of the table.
If they can, they're keeping it a secret.
My family bought a 1982 GM diesel. It was an absolutely atrocious car. Everyone that bought these diesels got burned. Lessons were learned.
"Everyone knows" that American buyers won't buy a diesel, just like "everyone knows" that American buyers won't buy a wagon.
http://www.landrover.co.uk/ownership/euro-6-emissions-standa...
Wow.
"The engine will only start again when the DEF tank is re-filled."
And thus the the "faulty DEF sensor" malfunction is introduced into our car fault lexicon.