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

tflcar.com

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

#41

Post by rasz_pl »

mberning wrote: post #9

The methodology here is highly suspect. First of all they are using an AWD dyno which can be unlinked to test a FWD or RWD car. It is expected that the car will dyno lower when driving the rear wheels as well as the front. Not only does it have to turn the drums of the dyno but also the rear wheels, tires, and brakes of the vehicle. Second, a key component of the cheat as reported by the media is keying off of the pr…

>will dyno lower when driving the rear wheels as well as the front

well, it did BETTER on four wheels spinning, so how is that a bad test?

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

#42

Post by kinofcain »

The most telling aspect of this is not the 10% power drop but the massive torque drop at lower RPMs. That indicates that VW is limiting turbo boost at low RPMs while in this mode. That makes sense, as increasing turbo boost increases pressure, which increases combustion temps, which increases NOx production.

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

#43

Post by Sanddancer »

nl wrote: post #31

So are they claiming that the software drops the engine into "cheat" mode by detecting when the front wheels were not spinning (which implies dyno-testing)? Is it confirmed that is how cheat mode worked? If I were writing this I'd be more inclined to look for known test cycle behaviour (ie, accelerate for a known time, then constant speed then stop, start etc etc) and drop into cheat mode when it is detected. I guess…

Other groups have stated the same thing [1]. The car already has to detect dyno testing to turn off traction control and other things that are dangerous under these conditions, adding a flag to tweak the mixture the car works with under speed isn't so difficult after that. Trying to detect a pattern would lead to much more complicated logic, especially if you get a tester who decides to do things in a different order.

[1] http://www.consumerreports.org/cro/cars/volkswagen-emissions...

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

#44

Post by toast0 »

acd wrote: post #29

I have an idea for a different test method. You take your cheating Volkswagen TDI without software fix to the local dragstrip on a day with little wind and do a series of test runs, you document your 1/4 mile time. Then you send in your car for a fix to Volkswagen most likely a ECU software update as that is cheapest fix. You retest your car at the drag racing strip, record the same number of runs. If the numbers bet…

That's a better test method, but since the VW fix is not available, it's worth trying something else. Although in this case, it seems the methodology is suspect: traction control applied brakes may be the source of the lost horsepower, and emissions weren't measured so there's no confirmation that the enhanced emission control mode was enabled either.

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

#45

Post by gnoway »

chubs wrote: post #32
msravi wrote: 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?

I believe VW have promised to replace everyones entire engines . I'm stupefied over how much this will cost, i've seen numbers around to 100B mark. Their market cap is somewhere near half of that. Presumably they think it's better than the brand damage otherwise. I think it's fair to assume they'll go bankrupt over this.

Do you have a link for this? Replacing even 500k engines in the US is indeed stupefying.

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

#46

Post by sandworm101 »

marincounty wrote: post #36
sandworm101 wrote: post #25

Earlier quoted context omitted.

The black stuff from diesels is soot, not smog. Soot is just unburnt carbon. The term 'smog' covers a whole manner of nasty chemicals, mostly oxides of nitrogen and sulfur. Soot is relatively harmless compared to smog. A diesel producing soot is running rich and therefore is arguably cleaner than a "clean-diesel" running lean and pumping out oxides. Those carbon-belching trucks are far better for your lungs than the…

Good post! Years ago I had a slight head gasket leak, and needed to drive the vechicle just one more day before I took the head off and did the nasty job. I had a little bit of extra smoke comming out of the tail pipe, and I got pulled over by a Police Officer. I told the officer, the extra smoke was mainly water vapor, but was still expecting a ticket. Well, the officer said he used to be a mechanic, and knew I was…

A leaky head gasket will usually produce a white smoke that smells a bit like pot smoke. That's the ethylene glycol in the antifreez/coolant being burnt.

The new anti-bleach craze is laughable. I had one woman at the local dog beach tell me "You know bleach is the same chlorine they use in swimming pools and we know that stuff causes cancer." I spend at least an hour a day swimming laps. Have done so since I was eight. And I at one point lived in a country where we regularly added small amounts of bleach to drinking water to disinfect it. If chlorine causes cancer I am doomed.

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

#47

Post by KMag »

ck2 wrote: post #34

The BBC did a real-world driving test and directly examined the exhaust for NOx emmisions and they were exponentially worse than the lab results. If the exhaust was going into your car, you'd be fatally poisoined in short order. So thanks for the cancer you've given to all the pedestrians and cyclists VW (and all the other lying corporate a-holes).

Not all toxins are carcinogenic. In particular, VW seems to have been leaning out the mixture, resulting in lower levels of soot and carcinogenic polyaromatics. I'm not aware of any studies showing oxides of nitrogen to be carcinogenic.

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

#48

Post by dghughes »

jessaustin wrote: post #39
dghughes wrote: post #38

Earlier quoted context omitted.

Off topic but I hate cars that don't allow traction control (TC) to be turned off it can be dangerous. We had Ford Transit vehicles at work and in the winter if there is a lot of snow the TC will kill 90% of engine power trapping you in the snow. I've almost been killed by TC on a Ford Transit activating at the worst moment. When I first drove the vehicle I had the vehicle stop abruptly when the TC kicked in and a ca…

ISTM the Transit's TC might just not be tuned very well? That might be related to the model year or might be something a Ford dealer could fix with a firmware update. Friends I've had in snowy places have sworn by their AWD vehicles. Personally I've scared myself half to death driving a big RWD truck in the snow.

Living in a snowy climate yes AWD and 4X4 are great yes (even FWD) it's the traction control that's the problem.

You can tell it wasn't designed by people who have ever seen snow. The Ford Transit is manufactured in Turkey but I don't know if that's a reason for the terrible traction control (and poor heat, and failing wheel bearings, and always cracking windshields).

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

#49

Post by dghughes »

jessaustin wrote: post #39
dghughes wrote: post #38

Earlier quoted context omitted.

Off topic but I hate cars that don't allow traction control (TC) to be turned off it can be dangerous. We had Ford Transit vehicles at work and in the winter if there is a lot of snow the TC will kill 90% of engine power trapping you in the snow. I've almost been killed by TC on a Ford Transit activating at the worst moment. When I first drove the vehicle I had the vehicle stop abruptly when the TC kicked in and a ca…

ISTM the Transit's TC might just not be tuned very well? That might be related to the model year or might be something a Ford dealer could fix with a firmware update. Friends I've had in snowy places have sworn by their AWD vehicles. Personally I've scared myself half to death driving a big RWD truck in the snow.

Living in a snowy climate yes AWD and 4X4 are great yes (even FWD) it's the traction control that's the problem.

You can tell it wasn't designed by people who have ever seen snow. The Ford Transit is manufactured in Turkey but I don't know if that's a reason for the terrible traction control (and poor heat, and failing wheel bearings, and always cracking windshields).

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