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

141–150 of 336 posts

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

#141

Post by 001sky »

dtparr wrote: post #111
001sky wrote: post #68

Earlier quoted context omitted.

that's no excuse, its basically ignorance. not personal critique, but still lots of people follow blindly things they don't understand.

Of course they do. People have limited time and energy and can't possibly be expected to have a good enough understanding of everything they touch in their daily lives to be able to "understand" them well enough to have sufficiently calibrated bullshit detectors for them all. Maybe you're an expert in ICEs and this was obvious to you. Would you notice if your cell phone charger was actually pulling 10 amps out of the…

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 also in terms of maintaining their political power base.

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

#142

Post by aleh »

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.

The only problem is that hardware to verify ECU code is an actual car of particular model with equipment to analyse exhaust. Or very precise mathematical model of it which would be much more expensive and would probably require super-computer to run.

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

#143

Post by 001sky »

ksk wrote: post #139
001sky wrote: post #68

Earlier quoted context omitted.

that's no excuse, its basically ignorance. not personal critique, but still lots of people follow blindly things they don't understand.

That's like saying someone threw a rock at you and because you didn't look around before it hit you, its your fault. The cheating is the problem, not the fact that people are ignorant about it.

no, its like saying "caveat emptor"

http://rockyroadblog.com/caveat-emptor-vetting-mpg-claims-30...

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

#144

Post by SeanLuke »

I wonder to what degree this is due to Europe's use, as I understand it, of an absurdly optimistic testing procedure (NEDC) which does not reflect real-world driving patterns.

https://en.wikipedia.org/wiki/New_European_Driving_Cycle

http://www.car-engineer.com/the-different-driving-cycles/

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

#145

Post by david-given »

anthony_d wrote: post #72
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've got an 2016 Audi A4. Audi claims 22mpg city, 32mpg highway and 26mpg combined. What I see is 24mpg city, 31mpg highway and 26mpg combined; I don't drive especially slow either. FWIW, I factory ordered a manual transmission so that may make a difference. I'm skeptical of cars that claim crazy high MPG ratings and performance cars claiming good MPG numbers, but for a standard car I do expect the numbers to be achi…

(You need to specify whether you're US or UK. Different gallon sizes! It makes US MPG ratings seem significantly worse than UK ones.)

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

#147

Post by JoeAltmaier »

david-given wrote: post #145
anthony_d wrote: post #72

Earlier quoted context omitted.

I've got an 2016 Audi A4. Audi claims 22mpg city, 32mpg highway and 26mpg combined. What I see is 24mpg city, 31mpg highway and 26mpg combined; I don't drive especially slow either. FWIW, I factory ordered a manual transmission so that may make a difference. I'm skeptical of cars that claim crazy high MPG ratings and performance cars claiming good MPG numbers, but for a standard car I do expect the numbers to be achi…

(You need to specify whether you're US or UK. Different gallon sizes! It makes US MPG ratings seem significantly worse than UK ones.)

And those darn Europeans measure it in liters-per-100-kilometer, just to make it worse!

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

#148

Post by andor »

Carmakers, not drivers, are the cause of the problem as obsolete official test results are being manipulated.

Then why does this report compare NEDC numbers with user-submitted real-world consumption? Since car manufacturers have increased power output while keeping NEDC consumption relatively constant, rather than the other way around, you need to drive very carefully to get close to the official numbers. It should be obvious that the more powerful an engine is, the more fuel it can burn in a period of time, if you go full throttle. Which is why they find that BMW and Mercedes deviate more than the average. Dear "Transport & Environment", why do you think do people buy fast cars?

This is the ICCT report TFA is based on: http://www.theicct.org/sites/default/files/publications/ICCT...

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

#149

Post by Shivetya »

pyb wrote: post #146

It's not really news though, is it ? All car magazines measure real consumption and show how it is much higher than the official figure.

well it really depends on how you drive as well. I have had only one car in the last twenty or so years where I could not consistently beat the EPA ratings. Plus throw in that most ares have ethanol formulations and that will lower your mileage.

Far too many race from light to light, keep on the gas even when going downhill and over the limit, brake late and even run with tires under inflated.

anecdotal, my current car a s28 Z4 uses a four cylinder turbo. 23/34 I think are the official ratings, I have yet to average a tank under 30 and did 40 on pure highway at speeds over 70. Granted its a manual which lets me abuse the rev range a bit more than the 8 speed auto offered but its simply down to learning to drive your car within its best performance parameters. I still have fun, run it up fast, but mostly just drive relaxed.

Does it mean that some cars are not performing to what companies claim. I am quite sure they aren't. I could not get a 2013 Mustang V6 above its EPA AVG to save my life.

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

#150

Post by schwabacher »

Someone1234 wrote: post #91
crazypyro wrote: post #39

Earlier quoted context omitted.

"3. Deducting 4% from measured results Bizarrely the NEDC procedure allows carmakers to actually declare (use) a value 4% lower than the one measured. The provision is designed to minimize the testing burden but is being abused by carmakers to declare lower test results systematically." I wonder if there is a person that didn't expect this to happen.

Does it matter however when it is systematic? This is going to sound backwards, but consider this: People buy cars based in part on MpG, however MpG is within itself an abstract thing (i.e. you don't actually get X miles per gallon, never did, never will too many other factors to include). So if everyone removes 4% from an abstract number, the entire market has shifted down, but the relative difference between two mo…

I can think of three reasons that it matters:

- We base regulations and taxes on absolute MpG, so overstating efficiency weakens the regulations and allows automakers to cheat on taxes.

- It misleads consumers about the cost to operate the vehicle.

- It is an issue when comparing efficiency of new cars to older cars produced before the systemic cheating.

Post reply on HN