Live data from Hacker News

Study: Some car models consuming around 50% more fuel than official results

transportenvironment.org

51–60 of 336 posts

Re: Study: Some car models consuming around 50% more fuel than official results

#51
post #2

"On average, two-thirds of the claimed gains in CO2 emissions and fuel consumption since 2008 have been delivered through manipulating tests" How deep does this rabbit hole go :( Here in Ireland the motortax for cars newer than 2008 is based on CO2 emissions, if motorists find their tax rising due to cheating by car manufacturers thats an unexpected and direct cost to their wallets.

None of this is really new, the mostly German car lobby has resisted European emissions testing on testing strict real-world usage, as opposed to testing on a roller.

Anyone who spent 10 minutes looking into this in the past years could've told you that, and it wasn't some big secret. A lot of it was stuff everyone was doing, like fitting certain tires and inflating them such that the rolling resistance is reduced. At the end of the day, there are limits to those gains and everyone does it, so in can't set you apart from the competition and once the basic manipulations are exhausted and the emissions goalposts are moved you can't make gains anymore without actually improving the car. Further most of these are for CO2 emissions / fuel efficiency, which is different from the VW fraud which was about NOx emissions.

The difference with the VW case is that VW essentially defrauded the test by building a device that measured various factors to establish whether it was being driven normally or whether it was being tested. In the former case it'd shut down (allowing 35x the legal limit of NOx emissions into the air while driving), while in the latter case it'd dampen the emissions (at the cost of engine performance, which is why they shut it off during regular driving). That's a different level of fraud, one that has very few bounds and can change results by much more than an order of magnitude, and is hugely controversial because it makes every test meaningless in the short, medium and long term and isn't practiced by everyone, and so different from manipulating tests by e.g. inflating tires which can still produce meaningful test, benchmarks and comparisons, when you start building 'defeat devices' all of that goes out the window completely.

Re: Study: Some car models consuming around 50% more fuel than official results

#52
More fuel consumption, more CO2. Clear.

But it's not the cheating story of VW, continued - that was about nitrogen oxide pollutants which was up to 40 times above what is allowed in the US.

From the report:

> All carmakers have been exploiting ever more flexibilities in the current official tests during 2013 and 2014, but detailed results from Spritmonitor in Germany (Figure 4) show that cars produced by Daimler, PSA and GM exhibit the largest realworld gaps, around 40%. However, in the past two to three years all major carmakers (with the possible exception of Fiat) have become more adept at using flexibilities in the tests such that all carmakers now have an average gap of 25% or more (as against a maximum gap of only 10% in 2001).

As I understand "Spritmonitor", as a private person, you can record your fuel data (from your receipt) and your odometer to calculate the mileage you can go with your car. No details about the driving behavior that has an impact on how much CO2 is emitted.

http://www.spritmonitor.de/en/overview/50-Volkswagen/0-All_m...

I guess that's not the perfect, reliable source - everyone can use the portal and add his favourite car. But for sure, I'll never reach the official 5.7 l/km with my car ...

Re: Study: Some car models consuming around 50% more fuel than official results

#53
post #29

If you read the full report, the automaker with by far the largest gap between its claimed improvements in fuel economy and its actual on-the-road performance is General Motors. Much worse than VW and Mercedes (who also did very poorly), by this measure. A reckoning is coming. source: see page 13, here http://www.transportenvironment.org/sites/te/files/publicati...

[deleted]

Re: Study: Some car models consuming around 50% more fuel than official results

#54
post #2

"On average, two-thirds of the claimed gains in CO2 emissions and fuel consumption since 2008 have been delivered through manipulating tests" How deep does this rabbit hole go :( Here in Ireland the motortax for cars newer than 2008 is based on CO2 emissions, if motorists find their tax rising due to cheating by car manufacturers thats an unexpected and direct cost to their wallets.

Or maybe we abolish nonsensical, contrary requirements? Whoever actaully believed the fuel consumption figures is a fool. You cant have a 1,5t of a car and expect it to use only 5l/100km. That's a good rate for a goddamn motorbike (450ccm,one piston, dont exceed 90 km/h and you might reach 4,5l/100km) Its one fifth of the mass...

Well sorry for being a fool then. It's impossible to investigate everything about every part of our lives, and personally I feel a bit cheated by these revelations.

I think most people are aware there could be cheating, but not on the scale being claimed. I don't think it's unreasonable to have placed a bit of trust in the number.

Re: Study: Some car models consuming around 50% more fuel than official results

#55
post #29

If you read the full report, the automaker with by far the largest gap between its claimed improvements in fuel economy and its actual on-the-road performance is General Motors. Much worse than VW and Mercedes (who also did very poorly), by this measure. A reckoning is coming. source: see page 13, here http://www.transportenvironment.org/sites/te/files/publicati...

From the third paragraph of your article:

>Mercedes cars have the biggest average gap between test and real-world performance, with real-world fuel consumption exceeding test results by nearly half.

Re: Study: Some car models consuming around 50% more fuel than official results

#56

This is the big next step that a lot of people were expecting - where in-depth studies into all of the competitors occurs and it's gradually revealed that this defeat device game has been played by almost everyone in the industry. It'll be interesting to see the repercussions for the automakers, but inevitably this'll end with sweeping legislation changes and reform of the testing protocol and standards.

Industry self-testing has always been a bad idea. You make it sound like legislation would be a bad thing here.

Re: Study: Some car models consuming around 50% more fuel than official results

#57
post #34

Earlier quoted context omitted.

I actually drove my Golf TDI at around the level of 5l/100km in Berlin for many years. Carefully. My girlfriend's Polo is significantly below that. Of course, these cars aren't ton and a half, but more around a ton.

[deleted]

I agree that cars are very heavy now, though, usually there are few 'types' of car weight. I do not know which where is used.

Usually there are 2 weights: unladen weight and maximum weight. I've heard about some third weight which is between the unladen and maximum weights, something like a car's weight with full tank and a driver, but don't quote me on this.

Probably you have the maximum weight listed. My Skoda Fabia (Audi Q3 equivalent) has maximum weight of 1680kg and unladen weight of 1200kg. I refuse to believe that VW Up is heavier than the Skoda Fabia.

AFAIK, minivans have quite big weight on their papers, but empty minivan can't weigh 3000kg, which is only possible if it's loaded.

Re: Study: Some car models consuming around 50% more fuel than official results

#58
post #29

If you read the full report, the automaker with by far the largest gap between its claimed improvements in fuel economy and its actual on-the-road performance is General Motors. Much worse than VW and Mercedes (who also did very poorly), by this measure. A reckoning is coming. source: see page 13, here http://www.transportenvironment.org/sites/te/files/publicati...

The source of the data is actually www.spritmonitor.de, which is a self-reporting mileage tracking site (like www.fuelly.com). With ~501k vehicles tracked and 8.885B kilometers tracked, the site represents ~17k kilometers per car of user-reported mileage information.

Is this the best, or a reliable source, of information to start the reckoning/witch hunt to come? I'm not sure.

Re: Study: Some car models consuming around 50% more fuel than official results

#59

Earlier quoted context omitted.

The reason air pollution is so much worse in European cities than American ones is largely due to diesel passenger vehicles.

See for example Paris's recent (yesterday?) "no car day" in the center. The city's usual blanket of smog is gone. France of course having the highest %age of diesel cars in its passenger fleet of any country.

Paris is one of the densest cities in the world[1], placed 6th if you disregard cities with a population of less than a million. It's the most dense large city among G8 countries. The only vaguely comparable European cities are Athens and Barcelona, both smaller and less dense. London has about a quarter of the density of Paris. The most dense large German cities, Munich and Berlin, less than a quarter. The city I live in -- part of one of the world's largest conurbations --, less than a tenth.

Statistics like these should be taken with a grain of salt (for one thing, city delimitations are fairly arbitrary), but the details are not worth haggling about: the point is that Paris is not at all representative of large European cities.

[1] if Wikipedia can be trusted on this https://en.wikipedia.org/wiki/List_of_cities_by_population_d...

Re: Study: Some car models consuming around 50% more fuel than official results

#60
post #29

If you read the full report, the automaker with by far the largest gap between its claimed improvements in fuel economy and its actual on-the-road performance is General Motors. Much worse than VW and Mercedes (who also did very poorly), by this measure. A reckoning is coming. source: see page 13, here http://www.transportenvironment.org/sites/te/files/publicati...

From the third paragraph of your article: >Mercedes cars have the biggest average gap between test and real-world performance, with real-world fuel consumption exceeding test results by nearly half.

Yes, your facts are valid too, but that's a different comparison than the one I am citing. Read my comment word-for-word and you will see the difference.
Post reply on HN