How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
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Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#2Wow, only a 10% loss? That hardly seems worth cheating... then again, I don't run a car company, so I guess it's the kind of thing they think they need to do. bummer.
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#3[deleted]
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#4This 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.
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#5Wow, only a 10% loss? That hardly seems worth cheating... then again, I don't run a car company, so I guess it's the kind of thing they think they need to do. bummer.
The real question is how it converts to mpg. A whole bunch of manufacturers have gotten in trouble for exaggerating fuel economy, and I for one certainly consider it when comparing cars (to an irrational degree, in fact). If it's the difference between 38mpg and 34mpg then that might be worth lying about.
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#6Wow, only a 10% loss? That hardly seems worth cheating... then again, I don't run a car company, so I guess it's the kind of thing they think they need to do. bummer.
The real question is how it converts to mpg. A whole bunch of manufacturers have gotten in trouble for exaggerating fuel economy, and I for one certainly consider it when comparing cars (to an irrational degree, in fact). If it's the difference between 38mpg and 34mpg then that might be worth lying about.
Especially if you're trying to meet US CAFE standards. Curious if VW is going to need to buy a bunch of ZEV credits now in CA (with Tesla being the primary beneficiary).
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#7Earlier quoted context omitted.
The real question is how it converts to mpg. A whole bunch of manufacturers have gotten in trouble for exaggerating fuel economy, and I for one certainly consider it when comparing cars (to an irrational degree, in fact). If it's the difference between 38mpg and 34mpg then that might be worth lying about.
Especially if you're trying to meet US CAFE standards. Curious if VW is going to need to buy a bunch of ZEV credits now in CA (with Tesla being the primary beneficiary).
Both CAFE and Smog Check-style programs are gamed terribly, across multiple manufacturers... but VW gets the blame, which it rightly deserves.
Testing of emissions needs to happen at the tailpipe while driving with mobile equipment in the real-world with certain types of traffic / road conditions.
Mileage needs to be calculated by metered fuel measurement on a test track with both highway- and (stop-and-go traffic) city-driving.
In addition to either two, Tesla vehicles and other full electric vehicles cannot come quickly enough to supplant gasoline/diesel/CNG/LNG/flex fuel/etc.
PS: I just California Smog Check'ed my '85 Vanagon, which has direct-port fuel injection, mass-airflow sensor and rudimentary "computer" (Digijet) after replacing the catalytic converter, O2 sensor and having a VW specialist shop tune it up. NOx (nitrous oxides) went from barely failing 15 and 25 mph limits to near zero. HC (hydrocarbons) and CO were also barely detectible. Emissions on it (a 90 hp motor) are currently at the levels of a PZEV or a new vehicle, and it gets 24 (real-world) MPG (9.8 L/100km).
Already, CA Smog Check station owners are foreseeing additional mandated equipment investments to perform tests on modern vehicles not just via the OBDII port under the steering wheel. This is a good thing but it's hard to sell small-business owners on capital and labor expenses up against the status quo/sunk costs fallacy.
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#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 based on those regulations?
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#9The 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 presence of the OBDII instrumentation. As far as I can tell they did not have any way of simulating this condition.
Re: How Much Power Does the Volkswagen TDI Lose in “Cheater” Mode?
#10While not conclusive, I give these guys credit for replicating a behavior fitting the "cheater" profile. But I am surprised that not spinning up the rear tires triggered that behavior.
The loss in power measured here will be very noticeable to diesel owners. Diesels have narrow power bands. You don't spend much driving time anywhere near the top hp zone. The torque curves are what matters. A 10% loss means you will probably have to rev up another 10%, say 3300 rather than 3000, to get at the same power. While a professional reviewer stepping into a car for the first time might not notice, the guy taking his personal vehicle in sure will. VW owners will not be happy if the coming fix reduces torque by this much.
I suspect this "cheat" is done by enriching the mixture a little to lower the temp and reduce NOx. Conversely, VW might have been running things too lean under normal operation. A lean (oxygen-rich) mixture burns hotter, resulting in more power and efficiency but much of that unburnt O2 ends up combining with N2 to form the nasty N0x junk. So if the fix means effectively pinning the cheat on all the time, fixed cars will probably end up burning more fuel with less top-end power.