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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

#161

Post by doczoidberg »

awjr wrote: post #107

Ok let's be real here, if we put the "pollution" taxes onto fuel and not on the design of the car, this problem, in effect, goes away. There is still the issue that high efficiency, usually means running the engine at high temperatures which generates far more NOx gases. We should be taxing the amount of fuel used.

Whole environment damage including the manufacturing should be taxed. Of course this can only be estimated.

Every engine and car produces different environment waste.

For example a Tesla S produces much more carbon in it's production than a gasoline car. There are also other toxins which are produced concerning different type of cars.

A diesel produces NOx but can reduce it with filters.

Just taxing the fuel used is just stupid.

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

#162

Post by JustSomeNobody »

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.

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

#163

Post by Nacraile »

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...

Your comparison with motorcycles is a bit flawed. Weight is the wrong thing to look at; at highway speeds drag is a major factor and motorcycles actually have higher drag coefficients than cars. You're also understating motorcycle fuel economy: I can easily get 4.5L/100km on my 600cc I4 doing 100km/h (although I more typically drive 130km/h and get 5L/100). I have friends who regularly do < 4L/100km in practice (on a 250, though).

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

#166

Post by userbinator »

bonzini wrote: post #118
vkjv wrote: post #86

Earlier quoted context omitted.

I thought the same. In my anecdotal experience, drivers tend to get much lower than the manufacturer mileage because they optimize for things other than fuel economy (e.g., speed). My dad taught me lots of tips on conserving fuel and thankfully I've exceeded the sticker numbers on every car I've owned.

No matter how careful I am, it's hard for me to get lower than 130% of the fuel consumption reported by the manufacturer. Perhaps I can do 120% of the reported consumption at 90 km/h, but I can hardly get lower than 140% on the highway (130 km/h) and in city traffic.

Are you in an area with much hilly terrain? That'll definitely increase fuel consumption significantly.

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

#167

Post by eveningcoffee »

petercooper wrote: post #123

I never pay attention to fuel consumption figures as they have never represented reality in my case. My current Mercedes has an official rating of 40mpg, but I never get that out of it unless I literally sit at 55mph on a flat motorway and never change speed (impossible in the UK). Some journeys I go as low as 19mpg when it's driven as it's meant to be. All the Vauxhalls I had before were the same.

This report does not include fuel consumption data - only emissions data (CO2 g/km).

While they speak about fuel consumption and even speculate with numbers, this is not backed up by the data.

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

#168

Post by eveningcoffee »

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...

If you read carefully then the report actually does not provide any data about fuel economy.

While they speak about fuel consumption and even speculate with numbers, this is not backed up by the data.

Report contains only data about CO2 emissions.

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

#169

Post by TheOtherHobbes »

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…

>you don't actually get X miles per gallon, never did, never will too many other factors to include

This wouldn't be hard to fix.

Loan cars to a random selection of non-professional beta drivers. Graph the results, showing the median and sd.

It would be cheaper to do this than to get hit by a class action for misleading buyers.

Of course reality-based non-expert mpg would look very bad compared to the dishonest figures you get now. But that's because of manufacturing and design decision, and not really the fault of the drivers.

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

#170

Post by toomuchtodo »

userbinator wrote: post #159
tremon wrote: post #152

Earlier quoted context omitted.

This is by no means an exhaustive list, nor an authoritative one. Would love to hear other's thoughts on these: - When accelerating, try not to over-extend the throttle. If the engine is at 2k rpm, you get just as much acceleration from 30% throttle as 100%, at half the fuel cost. - Release the throttle well before you reach a traffic light/stop sign. Deceleration by engine will cause a smoother stop and gives the tr…

Choose the highest gear when cruising You can do this for automatics too - you just have to learn where the shift points are and drive at the right speed. Lift up on the accelerator quickly to upshift, press it down quickly to downshift. One thing that I notice easily when riding is when the driver is constantly staying at only a few km/h slower than the shift point, causing the engine to spin faster and consume more…

You can usually get the shift points for a model from its technical manual. Depending on the car, those shift points can be modified as well (using the appropriate software and cable).
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