Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

transportenvironment.org

Post reply on HN
Print view View original

171–180 of 336 posts

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

#171

Post by vonmoltke »

pbhjpbhj wrote: post #41
mpweiher wrote: post #31

Earlier quoted context omitted.

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.

> Isn't that where catalytic converters come in though?

Diesel exhaust is too oxygen-rich for the cat to effectively catalyze the NOx. That's why recent passenger car diesel systems have a Diesel Exhaust Fluid system.

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

#172

Post by lucaspiller »

kwelstr wrote: post #138
nathancahill wrote: post #120

Earlier quoted context omitted.

Accelerate gradually, stay off the brakes.

And when in the highway don't go too fast, speed increases drag etc. etc.

I did some tests on a long drive last week, for the Smart Forfour I had this was the fuel consumption. It was all along flat, straight parts of the highway. Reports were based upon the cars own fuel efficiency monitor.

- 135 km/h 7.8l/100km (30 mpg)

- 125 km/h 6.5l/100km (36 mpg)

- 115 km/h 5.4l/100km (43 mpg)

I never realised speed made such a difference!

(Mpg is US gallons)

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

#173

Post by JonFish85 »

JustSomeNobody wrote: post #162
Bud wrote: 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...

Assuming wrongdoing: GM will get another pass because it is "too big to fail." This has to stop. Execs need to start going to prison.

You're also assuming that execs necessarily knew about everything. There's a reasonable chance that the execs set the targets and feed it to the middle managers who pass it along to teams.

Somewhere along the line I imagine there are those who are terrified of missing those targets and perhaps losing their jobs and resort to bending the rules a bit to hit their goals. And there's a very good chance that these people aren't at the top.

The same was most likely true in the subprime mortgages--I imagine that some of the worst actors in that weren't necessarily the people at the top, it was the guy who is decidedly mid-level who is looking to make a nice bonus to put in a swimming pool for his kids.

And to figure it all out is going to take years and years of investigations to assign blame (whether in this case or in the subprime case). By the time it's sorted out, it could be a decade after the fact, and even then people have moved on to other jobs, records are difficult to dig up, and at the end of the day, what has been accomplished?

Of course if there is blatant wrong-doing, execs should absolutely be punished (the peanut company CEO comes to mind [1]). But it's extremely difficult to pin down blame on any one person, exec or not.

[1] http://www.reuters.com/article/2015/09/22/us-usa-georgia-sal...

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

#174

Post by 001sky »

mfringel wrote: post #157
001sky wrote: post #141

Earlier quoted context omitted.

They didn't call those bands "rage against the machine" and "public enemy" for nuthin now did they? I mean, in all seriousness, why be so serious? Simple points need to be understood, not simply dismissed out of hand. In theory everything the government or your employer tells you is true. In reality, they have alot to gain from asymetric information distribution, both in terms of negotiating financial outcomes but al…

Have you checked your keyboard's electrical path for surveillance equipment this morning? Did you test your water for drugs this morning? Did you check them yesterday? We all live at certain layers of abstraction.

Have you ever measured a 2x4?

probably not

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

#176

Post by TrevorJ »

mattlutze wrote: post #58
Bud wrote: 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.

Well the sample size is good. You could validate the data by comparing self reported averages against actual averages from a sample group.

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

#177

Post by JonFish85 »

fithisux wrote: post #17
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.

Not their wallets. why should they pay for the fraud of corporates? Let the corporates replace cars .

One way or another, regular folks will pay for it. If it's directly by paying this tax, that's straight forward. Otherwise, the company will take the hit, and the cost will flow towards stock-holders, which in general tend to be unions, 401k plans and such. How much of your 401k are you willing to lose due to that cost? How much of your parents' 401k/union pensions is OK to forfeit?

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

#178

Post by Karunamon »

JonFish85 wrote: post #173
JustSomeNobody wrote: post #162

Earlier quoted context omitted.

Assuming wrongdoing: GM will get another pass because it is "too big to fail." This has to stop. Execs need to start going to prison.

You're also assuming that execs necessarily knew about everything. There's a reasonable chance that the execs set the targets and feed it to the middle managers who pass it along to teams. Somewhere along the line I imagine there are those who are terrified of missing those targets and perhaps losing their jobs and resort to bending the rules a bit to hit their goals. And there's a very good chance that these people…

The execs get all the credit when it goes right, they should get all the blame when it goes wrong.

Lock a couple of these people up, and suddenly they'll start caring a lot more about the legality of what their underlings are doing...

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

#179

Post by nradov »

pjc50 wrote: post #9
happyscrappy wrote: post #3

Earlier quoted context omitted.

Europe was really led astray when they were told that diesels were better for the environment, hybrids would have been the way to go.

Europe has 'bet on diesel' for many years while hybrids have only recently become available.

Hybrid cars have been available in Europe for 15 years. So not that recent.

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

#180

Post by kevin_thibedeau »

Roboprog wrote: post #129
[deleted] wrote: post #34

Earlier quoted context omitted.

[deleted]

And how. My old '89 Chevy S-10 weighed just over 1700 pounds (770 kg) empty. At 55 MPH (90 kph) on the freeway (back when that was still the limit), it got about 30 MPG (13 km/l / 7.7l/100km). OK, not great mileage, but what do you want for 80s US car tech :-) For safety reasons, or whatever, they don't make mini trucks in the US any more. I did a double take on a new Dodge "Dakota" in the store parking lot the other…

It wasn't for safety. Compact trucks have too small of a footprint to get away with the CAFE requirements for their size so manufacturers either supersize them (Dakota) or eliminate them altogether (Ranger).
Post reply on HN