Is Smokey Yunick running VW these days?

[Baron Von Crowder]

I can only imagine the VW engineer's chatting about this.

"How the hell are we supposed to make an efficient running engine when they want us to put the dirty air back in it?"

"That's going to kill the MPG ratings we've worked so hard on"

"hey guys, how bout we fuck with them US assholes, and just turn on the emissions crap when they are testing it? That way we keep the fuel consumption down!"

[Tyrone Biggums]

What does this actually mean for the consumer?

My guess is a pissed VW owner with possible grounds for legal action. If the vehicle is required to run on the epa tune I would imagine fuel economy and performance may suffer and no longer meet numbers "advertised" when the vehicle was purchased.

From a redditor:

"So the short answer is still quite long.

They were caught cheating on NOx emissions primarily although all emissions are in a way connected.

NOx is created when temperatures and pressures are very high during combustion. Sadly NOx emission is generally higher when your combustion is nice and hot and rapid, which gives higher efficiency (closer to the ideal thermodynamic cycle).

So In general if you calibrate the engine with a combustion recipe that atomizes fuel quickly and mixes well youll get more NOx.

There are couple of important trade-offs then. Low soot/good combustion = Higher NOx and Low fuel consumption = higher Nox.

The EPA therefore defines "clean" as having BOTH low soot AND low NOx, and since those two things are hard to achieve together it takes a good bit of engineering, and in todays world some aftertreatment to achieve it.

EGR (exhaust gas recirculation) Particulate filters Oxidation catalysts and SCR calalysts (using Urea as a reactant) all are ways of reducing these combustion products while trying to maintain decent fuel consumption

But in VWs case what they did was teach the ECM to recognize when it was being tested. At that time it would switch to the "clean" map. Clean meaning that it meets EPA requirements for both NOx and soot.

Then when the test is over (and potentially an OBD drive cycle) it would fall back to its primary driving map. On the driving map it would have been optimized for best fuel economy and performance. Optimized in this case refers to the fuel injection pressure and timing, and possibly EGR and Urea flow, parameters controlled by the ECM.

Specifically earlier injection timing gives better power and efficiency but creates more NOx. NOx by the way is totally invisible and odorless.

The end result is an engine that will pass an EPA engine emissions certification test, but then will recalibrate itself for driving or (ironically) for the EPA mpg test cycle (which is done in chassis without emissions monitoring). Thus the engineers get to circumvent the very difficult trade-off between NOx and efficiency. The car will produce a lot more NOx in normal driving, and have better fuel economy. Technically not meeting the intent of the emissions law but very hard to detect.

If VW correct this via recall the car will be required to run on the "clean" calibration all the time. This will mean poorer fuel economy, I would be speculating to say by how much but VW wouldnt have bothered cheating if it wasnt a significant gain. It may even have implications on durability if certain parameters (like exhaust gas temps, turbocharger RPMs or oil life) are affected as they often are."

[BP]

Who gives a shit? What does this actually mean for the consumer?

People that live in places like California and NY aren't going to be able to register their cars until the recall is performed and any VW/Audi dealer with one in inventory isn't going to be able to sell it until the recall is completed. A recall that hasn't been figured out yet btw. If they have to retrofit every car with a UREA system it'll cost VW thousands of dollars per car.

Not only that but these engines have been fairly reliable, with the new tuning they will likely start having loads of EGR cooler problems like most of the trucks have. Which is going to kill their market value. Not to mention the drop in fuel economy and performance they'll have.

[Baba Ganoush]

Knew a chick with the intials VW, dirty little slut she was.

Chicks that drive German cars = hot

[Sean88gt]

Which brings up another question, does the mileage improvement (and reduction in fuel usage) have more positive environmental effects than the reduced NOx, (and increased fuel usage)?

[BP]

Which brings up another question, does the mileage improvement (and reduction in fuel usage) have more positive environmental effects than the reduced NOx, (and increased fuel usage)?

Or an even better question would be how much NOx is produced every day by diesel powered cars compared to natural sources like lightning strikes. That and once NOx reaches the stratosphere it fills in the Ozone layer which can contribute to global cooling. So it might actually be good for the environment.

One thing is for certain though, increased fuel consumption means an increase in fuel tax revenue. That and if it hurts VW it should help GM/Ford since they offer competitive models with turbocharged DI gasoline engines with an unproven track record.

[svauto-erotic855]

Which brings up another question, does the mileage improvement (and reduction in fuel usage) have more positive environmental effects than the reduced NOx, (and increased fuel usage)?

The answer is a resounding YES!!!!!

Ford and GM did an extensive amount of research about this and found that NOx doesn't do much of anything. CARB had to come along and make up a bunch of unfounded BS concerning NOx in a DELIBERATE effort to drive small high efficiency diesels out of the US market because they were a threat to CARBs wet dream of mandating electric cars. Just look at the absolute raving fucking shit fit CARB officials threw when Honda brought out the 95' Civic that had no measurable tailpipe emissions and the air out of the tailpipe had lower HC emissions then the ambient air. CARB refused to certify it as a zero emissions and went and spent a couple of hundred MILLION dollars designing new equipment that could measure tailpipe emissions from the Honda.

[fastwhite99gt]

If the "fix" hurts mileage very bad, they can stuff it, Alaska doesn't do emissions testing anyway. The wife's Passat gets like 36-37 in town and 43-44 at 80mph. If it didn't have warranty left, they make all the parts to delete every bit of that crap and I bet it would get over 50 on the interstate.

[2011GT]

Not sure why people even buy the diesel. The upfront cost is huge and the fuel cost is more. Do the math and you're more than likely to never come ahead.

[David]

Because diesels are fucking awesome.

[snacksnack]

Not sure why people even buy the diesel. The upfront cost is huge and the fuel cost is more. Do the math and you're more than likely to never come ahead.

The cheapest Jetta on vw website starts at 18780, the tdi starts at 21640 with the hybrid in the 30's. How is that a huge upfront cost considering the cheapest tdi comes better loaded then the cheapest gas one.

[2011GT]

Edit: I could have swore the diesel version was only offered on higher trim models so the cost was a bit much. If you want to "cool" factor get a diesel. But I wouldn't trust a vw anyways. The few people I know that have owned one hated them.

That's nearly a 3k difference for about 7mpg more in the hwy. figure in the difference in fuel cost which is about 50 cents more per diesel where I live and you're never going to come ahead. I think players are too late to the diesel game. It made sense at one time but it doesn't anymore. It can also be more difficult to find fuel.

[fastwhite99gt]

The DSG takes some getting used to, but the wife loves the huge back seat for the girls. Decent sized trunk, comfortable and going from a 1/2 ton truck to the Passat saved her a fortune in fuel running through town to work.

[fordracing19]

I like my 600+ miles per tank in my Passat. I think the car drives great. I put 2k miles a month on and think its totally worth it.

[snacksnack]

Edit: I could have swore the diesel version was only offered on higher trim models so the cost was a bit much. If you want to "cool" factor get a diesel. But I wouldn't trust a vw anyways. The few people I know that have owned one hated them.

That's nearly a 3k difference for about 7mpg more in the hwy. figure in the difference in fuel cost which is about 50 cents more per diesel where I live and you're never going to come ahead. I think players are too late to the diesel game. It made sense at one time but it doesn't anymore. It can also be more difficult to find fuel.

The best part is while they claim a rather low city mpg I never very but 5 mpg from best to worst so assuming you don't 100% of the time drive highway which I don't it beats the gas by a much better percentage. Then you have the power side of it, the torque is so noticeable and nice that it makes it well worth it. For the record I have love these cars it doesn't cost anymore to drive then any other car except the cost of the diesel which has only been around 20-25 cents difference lately.