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

transportenvironment.org

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

#41

Post by pbhjpbhj »

mpweiher wrote: post #31
emp_zealoth wrote: post #16

Earlier quoted context omitted.

Im pretty sure its just a case of completely out of control rules - they became impossible to follow, so everyone just decided to "play along"

Also rules that are in conflict. To get good mileage and corresponding low CO2 emissions, you need ultra lean mixtures. Alas, ultra lean mixtures produce more NOx. You want low NOx emissions, you need richer mixtures, and thus higher fuel consumption and higher CO2 emissions.

>ultra lean mixtures produce more NOx //

Isn't that where catalytic converters come in though?

Rules in conflict surely are required by the chemistry of the situation, the companies have to search for the local minima in order to comply.

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

#42

Post by alkonaut »

The thing is that the cheats (throwing out unnecessary weight, taping door gaps etc, using super hard notrogen inflated tyres, etc.) would add a constant amount to the fuel consumption, say .2 liter per 10km.

If you keep pushing your engine consumption downwards to the ridiculous levels we see now (Just goes to show that the cars should be designed without large door gaps or outside mirrors (cameras instead) and so on, since they seem to add significantly to the consumptions that that is where the effort should be put.

As a consumer, I really don't care much, I just get consumption data from some independent source such as a magazine or website. Having manufacturers self-test and self-regulate reminds me of the financial industry in 2008. It just won't work.

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

#43

Post by axx »

eterm wrote: post #20
axx wrote: post #14

I think we all should agree that this is the same for every car manufacturer (except electric). Sure, european manufacturers are the target now, but i expect same results from all other manufacturers (including asian and american). Lab results never represent real street results. How could they? People drive differently and the outcome is based on many aspects that you can't reproduce in lab conditions.

You are obfuscating the issue here. The issue isn't that we can't "represent real street results", the issue is that manufacturers took deliberate steps to alter car behaviour with the intention of obtaining better test results than would be present outside the tests.

And that's a surprise to whom?

It's the same with smartphone and notebook batteries. Tell me, when was the last time, you actually got 9 hours of battery live (in case of a MBP)?

Don't get me wrong, i see it the same way as you are, but this is an issue that you can find everywhere not just in car manufacturing.

For example, a lot of power supply companies try all kinds of tricks to game the efficiency test systems.

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

#44

Post by slasaus »

Zigurd wrote: post #25
solaris999 wrote: post #7

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.

This is a very good bet. The "defeat device" turns out to be using a feature of the ECU platform provided by the ECU supplier. It would be surprising to find that VW was the only maker to cheat, when the cheating mechanism was available to everyone. There are some markets, like voting machines, where requiring open, buildable, verifiable code is good practice. Cars might be another.

I was thinking of voting machines as well and think publicly verifiable code and hardware would be a good thing for cars (I don't think it's good enough for large scale elections, but that's another topic).

See this story about the need for open source for large publicly used systems: http://www.nytimes.com/2015/09/23/nyregion/volkswagens-diese...

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

#45

Post by jameshart »

happyscrappy wrote: post #19
padelt wrote: post #11

Earlier quoted context omitted.

> Europe was really led astray when they were told that diesels were better for the environment Were we led astray? Or are we discussing the last few percentages beyond an actual advantage over gasoline engines?

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

That goes against my subjective experience. The contribution of buses and trucks in US cities is also significant, and my sense is that EU regs on those vehicles are more stringent than US. I particularly tend to notice how much -noisier- large US vehicles are than European equivalents in a city traffic environment, which tends to correlate with lower efficiency.

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

#46

Post by trymas »

mpweiher wrote: post #22
emp_zealoth wrote: post #8

Earlier quoted context omitted.

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...

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.

Yup. Diesel cars can pull of 5l/100km quite easily (even VW Passat from 1998 can do that). My diesel Skoda Fabia consumes 4.6l/100km at 90kmh in highway. If conditions are not terrible, I hover around 5l/100km on average in mixed conditions (city and highway). Though few major traffic jams can ruin statistics pretty badly. Also in winter average is about 5.6l/100km.

Maybe /user/emp_zealoth had petrol cars in mind? I've not personally seen a petrol (non hybrid) car consuming less than 7l/100km and when I had one it was 10l/100km (8 if I was lucky) and it was small Peugeot 306.

To rant even more.. IMHO, those fuel consumption tests are a total fraud. Look at new diesel sedans, local dealer declares that huge VW Passat TDI uses 4l/100km, or Skoda Octavia TDI (GreenLine or something) uses 3.1l/100km. Maybe it's true when you're driving at 90km/h with wind blowing in your tail and slight downhill.

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

#47

Post by mpweiher »

[deleted] wrote: post #34
mpweiher wrote: post #22

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]

Yeah, I checked for the Polo, empty weight appears to be 1050 kg. The Golf TDI was a '96, so given the trends I expect it to be roughly similar. The original Golf I was under a ton.

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

#48

Post by [deleted] »

silon7 wrote: post #26
emp_zealoth wrote: post #8

Earlier quoted context omitted.

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...

It's achievable with a diesel and not too-heavy foot easily (possibly with some extra NOx ;-)

[deleted]

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

#49

Post by morsch »

emp_zealoth wrote: post #8
yc1010 wrote: 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...

The requirement was to incentivise more efficient cars. Manufacturers just decided to ignore the requirement and lie about it instead. Customers decided to believe them.

Cars keep getting bigger and heavier. The current Golf -- nominally a compact car -- is half a meter longer (at least 4.25m) than the first one and half a ton heavier (at least 1.2t).

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

#50

Post by happyscrappy »

wil421 wrote: post #18
mgiannopoulos wrote: post #4

So, any Japanese or American companies doing this as well? Who's next?

For now the answer is inconclusive, but let's wait and see what tricks the gasoline models are playing. The Chevy Cruze Diesel was as clean as promised in the US version but the European version may not be as clean[1]. http://www.thetruthaboutcars.com/2015/09/tech-dive-chevy-cru...

European emission rules are lax compared to American ones so it may well be dirtier but legal.
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