Given the recent news from VW, the ability of your car to deliver satisfactory performance AND meet emissions requirements is now in doubt. I could probably get a gasoline spark-ignited engine to deliver astonishing power (run it rich when accelerating) and great fuel economy (run it lean when cruising), if I could get the EPA to look the other way.
Exactlly. It’s almost certain (probability well above 90%) that they switch off the emissions controls because the performance is horrible when it’s on. Assuming that the VW engineers are not a bunch of Captain Planet villains, that’s really the only reason why they would do something like this.
Unless you feel that deliberate, willful production of vehicles that spew 40X the legal emissions limit somehow does not make them CPVs, that’s exactly what they are: they have formally admitted that their intent was to skirt environmental protection regulations. They deliberately chose to foul the air, in contravention of the laws that the other manufacturers abide by, so they could make money.
EPA’s official information says that NOx emissions are the problem. I don’t know the specifics, but my guess is that it was as simple as advancing the injection timing so that combustion takes place earlier in the expansion stroke, closer to TDC. This would improve power and fuel economy, but the increased combustion/post-combustion temps would jack up the NOx output. This is something that was also done by a bunch of heavy-duty diesel engine manufacturers (Caterpillar, Cummins, etc.) back in the late 1990s (and they too were caught and heavily fined).
Because you don’t buy a used car from a manufacturer. They haven’t made any warranties to you.
Or, for a more direct comparison, VW’s own 2.0 turbo gas engine makes 210 horsepower and 258 foot pounds in its current iteration.
The VW 2.0T gas engine produces maximum power at 4500 RPM and maximum torque at 1500 RPM, and revs to 8000. The diesel produces maximum power at 3500 RPM (which is close to the top of its rev range) and maximum torque at 1750 RPM.
Nissan does very well in the UK. In fact, its largest single factory (in terms of vehicle output) is in Sunderland. The major Japanese manufacturers are all somewhere around the top 15 in other major European economies, too. They certainly don’t have the market penetration they do in the US but that is largely a function of European import quotas (which result in only middle and upper segment models being sold since they are more profitable per vehicle).
there appear to have been more than one thing going on. I’ll try to find where I read it, but the two key points the researchers found:
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on cars using lean NOx traps (no urea SCR) they were using more EGR on the test to produce less NOx. on the road, EGR aspiration was cut back or eliminated, leading to too much NOx generation for the trap to handle.
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on the one or two models with DEF (urea solution,) they were using full DEF dosing for the test but not on the road. This one I can’t figure out, DEF is cheap. $15 gets you 2.5 gallons, and on a truck like an F350 5 gallons lasts about 7500 miles.
More EGR would likely mean more soot production. Maybe they were counting on not clogging the particulate filter during brief emissions tests? Not sure how they can easily fix this one on the vehicles already sold.
But a VW sedan probably doesn’t hold 5 gallons of DEF. The easy remedy for VW in this situation is to go with full DEF dosing during normal driving, but this would mean more frequent refills for the owner. May not cost all that much, but if you’ve gotta pop the hood and refill it every couple thousand miles (and keep a jug of DEF handy in your garage), that adds significant hassle.
If VW was able to do this undetected for so long I have to wonder if some other manufacturers aren’t doing similar things. How many frantic boardroom meetings are occurring right now?
Neither.
I’m aware and thought that was clear. I was just pointing out something that could be easily misunderstood, if not by you, than by others.
The cheating is what I was talking about. It led to a consent decree to basically improve emissions faster than scheduled:
From Dieselnet:
*Consent Decrees. Most engine manufacturers were required to comply with the 2004 emission standards as early as from October 2002, 15 months ahead of the regulatory schedule. In October 1998, a series of court settlements were reached between the EPA, Department of Justice, California ARB and engine manufacturers—Caterpillar, Cummins, Detroit Diesel, Volvo, Mack Trucks/Renault and Navistar—over the issue of high NOx emissions from heavy-duty diesel engines during certain driving modes. Since the early 1990’s, the manufacturers used engine control software that caused engines to switch to a more fuel efficient—but higher NOx—driving mode during steady highway cruising. The EPA considered this engine control strategy an illegal “emission defeat device”. *
I don’t know if it would cause a test failure; AFAIK the typical re-gen schedule is somewhere between every 300 to 600 miles depending on how the vehicle’s driven.
it also doesn’t have a 6.7 liter engine nor weigh 7,500 lbs.
doesn’t justify it. if it’s a case where you can’t package that in the existing car, then you just have to drop that model until you can incorporate a larger tank in a refreshed/re-designed car.
I’d wager GM, Ford, and Chrysler would probably not try to pull anything like this since the truck industry has been to this dance.
Is that a typo or do they really use urea?
VW owns Scania, which was presumably following the Navistar lawsuits. Didn’t help them.
I was talking about what VW might do to remedy the already-existing cars that are the subject of this scandal. How do you modify them to bring them into compliance? Increasing the DEF flow rate should work, but owners will not be happy if they have to refill the DEF tank every month or two.
Not a typo. The fluid is a 32% solution of urea. They dye it blue, for the same reasons that tampon ads always use some mysterious blue fluid 
They really do. In the heat of the exhaust stream, the urea breaks down into ammonia, which helps catalyze the reaction that breaks NOx down into N2 and O2.
That is kind of hard to believe since there is no such thing as a gasoline TDI engine. 
“TDI” stands for “Turbocharged Direct Injection.” there are a hell of a lot of gasoline, turbocharged, direct injection engines out there now.
I have one, because it [2006 Jetta, bought it in 09] cost me $16 K after all the taxes, registration and all that crap was added in. Insurance is hella cheaper than a hybrid and the damned thing gets 42 MPG … and I don’t have the caustic heavy hazmat burden battery bank that needs replacement after a few years … why the hell should I go into debt buying a hybrid and dealing with the double hazmat burden of the batteries? Oh, and I can also change to biodiesel as a fuel any time I want with minimal fuss.
[only thing better would have been if it had been manual instead of automatic, but I am funny that way.]
"From Wikipedia, the free encyclopedia
Volkswagen Group products which feature a TDI engine display a TDI badge
Turbocharged Direct Injection or TDI [1] is a design of turbodiesel engines, which feature turbocharging and cylinder-direct fuel injection,[1] developed and produced by the Volkswagen Group.[2] These TDI engines are widely used in all mainstream Volkswagen Group marques of passenger cars and light commercial vehicles produced by the company[3] (particularly those sold in Europe). They are also used as marine engines - Volkswagen Marine,[4][5][6] and Volkswagen Industrial Motor[7] applications.
In many countries, TDI is a registered trademark of Volkswagen AG.[2]
The TDI designation has also been used on vehicles powered by Land Rover designed diesel engines. These are unrelated to VAG engines."
Care to show me where they mention TDI being used for anything but a Diesel engine. Yes there are turbo charged gas engines… and yes there are turbo charged fuel injected gas engines. But there are no “TDI” gas engines.
The amount of mental gymnastics VW apologists will go through to justify their shitty purchases never ceases to amaze me. It’s incredible that these cancerous shitmobiles are still allowed on the streets when notable environmental stalwarts like China ban diesel pass cars more or less outright.
BTW JZ any idea when they are going to start mandating urea injection on DI gas engines too for NOx?