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How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

tflcar.com

11–20 of 49 posts

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#11
>if you look lower on the RPM curve the difference is significant. The car lost 15 horsepower around 2,800 RPM, and 32 lb-ft of torque near 2,700 rpm

so, looking at the picture, the power/torque at 2800rpm is about 120/260 while in "cheater" mode it is 105/228. And that ratio is preserved through whole 2000-3000rpm range, the range that really matters as most of the driving happens here.

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#12
VW owners may be looking at the kind of retrofits California requires for older heavy trucks.[1] The muffler is replaced with a filter which has to be cleaned periodically. This seems to be working; it's rare to see a truck belching smoke in California. So there's a path to a fix available.

[1] http://www.arb.ca.gov/msprog/truckstop/truckstop.htm

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#13
post #12

VW owners may be looking at the kind of retrofits California requires for older heavy trucks.[1] The muffler is replaced with a filter which has to be cleaned periodically. This seems to be working; it's rare to see a truck belching smoke in California. So there's a path to a fix available. [1] http://www.arb.ca.gov/msprog/truckstop/truckstop.htm

I always see large trucks on I-5 regularly spewing huge amounts of smoke when they hit the gas. It gets so bad that people speed around them to avoid the smog getting into their cars. This is mostly large commercial semis and dump trucks. Are you talking about passenger cars?

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#14
post #12

VW owners may be looking at the kind of retrofits California requires for older heavy trucks.[1] The muffler is replaced with a filter which has to be cleaned periodically. This seems to be working; it's rare to see a truck belching smoke in California. So there's a path to a fix available. [1] http://www.arb.ca.gov/msprog/truckstop/truckstop.htm

I doubt that NOx can be captured by such a filter. And according to the article particles level is already well below the limit.

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#15
post #8

> The acceptable particulate level in Colorado emissions testing is 35% opacity. That means the smoke and particulates that are coming out of the exhaust pipe can block up to 35% of light and pass the test. This is a lot of smoke. This is the most shocking part of this... can you really pass with that much smoke coming out the tailpipe? That's absurd and I find it hard to believe. What's even the point of testing bas…

The 35% is a meaningless number without more details. It's not shocking at all if a 1km column of smoke blocks more than 35% of the light passing along it. So we need to know more about the test to decide if it's shocking or not - specifically the distance the light travels through the sample.

Integration time is also important. Short bursts of dense smoke can be equally polluting as a continuous stream of light smoke.

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#16
So now, given that "fixing" the problem will cause power loss, and consequently adversely affect fuel economy, wouldn't a number of VW owners opt not to bring in their vehicles for the recall? What's the incentive for VW owners to voluntarily bring in their cars for a regressive (in terms of power and mpg) fix?

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#18
post #16

So now, given that "fixing" the problem will cause power loss, and consequently adversely affect fuel economy, wouldn't a number of VW owners opt not to bring in their vehicles for the recall? What's the incentive for VW owners to voluntarily bring in their cars for a regressive (in terms of power and mpg) fix?

Also given that this effects the quality of the product they bought significantly, wouldnt they be entitled to a refund?

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#19
post #16

So now, given that "fixing" the problem will cause power loss, and consequently adversely affect fuel economy, wouldn't a number of VW owners opt not to bring in their vehicles for the recall? What's the incentive for VW owners to voluntarily bring in their cars for a regressive (in terms of power and mpg) fix?

The incentive is that, in states that have mandatory smog checking, you will not be able to renew the registration on your car until you get it fixed, rendering it illegal to drive

Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?

#20
post #4

This test seems very poor. They didn't measure the NOx emissions so we don't know if it really entered "cheater mode". According to a comment there, it was probably trying to compensate for what it detected as the rear wheels spinning and they need to turn off DSP. It doesn't sound like they really knew what they were doing so I'm not sure I trust it.

Yeah, also a power run on a dyno is nothing like the sustained cruising-speed tests carried out for emissions tests. I'm not sure that during a power run the car would realize it is being tested. At least, it wouldn't if I was the one implementing the cheat-mode based on my knowledge of emissions testing procedures.
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