Mercedes Benz OVERSTATING fuel consumption

Zero_Gravitas

In fact, they are understating the fuel consumption (i.e. saying that the car uses less fuel than it actually does) and ovestating the mpg (i.e. saying that the car does more miles per gallon than it actually does).

Either way, this is not really news.

Best Regards,

ZG.

PS - sorry, cross-post with nid0 above...

uniqu3

As above mainly.

People will slag off the mpg of a car without taking into account how they are driving it. MPG figures usually have the caveat that they are conducted in test conditions as set by European Standards.

There's not much recourse for complaining, especially with things as per below, with a 300 mile or so journey on public roads.(MPG Marathon Competition)

https://dl.dropboxusercontent.com/u/36613906/MPG%202014/MPG%20Marathon-Results-2014.pdf

if you're not comfortable with the link, see here: http://www.thempgmarathon.co.uk/the-results/

In that test, two young formula ford drivers (lad & girl) got over 75mpg from a Fiesta ST-3, while another got 97 mpg from a 1.6TDCi. Bear in mind, they are rigorously adjudicated tests.

The only factor in most of the cases, especially when you think about the evidence, is that it's down to driving ability and/or car condition (i.e. tyre pressures and so on).

Hyundai and Kia have been punished for the issue in the US, however, so things could change.
http://www.autoexpress.co.uk/hyundai/89305/hyundai-and-kia-in-record-fuel-economy-settlement

AdrianC

Not only are M-B doing no wrong in using those figures, but it would actually be illegal for M-B (or any other manufacturer) to claim any other figures than the standardised test results.

http://www.dft.gov.uk/vca/fcb/the-fuel-consumption-testing-scheme.asp
explains exactly how the figures are arrived at.

Ebe_Scrooge

Exactly as has been pointed out previously, the tests are a standard measure to allow you to compare one car with another, and are in no way intended to represent real-world consumption - indeed, many adverts now state this in the small print. In the real world there are dozens, if not hundreds, of variables that will affect consumption - driving style, traffic, weight being carried, electrical equipment being used, road profile, engine wear, maintenance, and many many others. It would be all but impossible to predict real-world figures. As a previous poster pointed out, Honest John has a section where readers submit their own figures, that can at least give you a more realistic average.

OddballJamie

AdrianC wrote: »

Not only are M-B doing no wrong in using those figures, but it would actually be illegal for M-B (or any other manufacturer) to claim any other figures than the standardised test results.

http://www.dft.gov.uk/vca/fcb/the-fuel-consumption-testing-scheme.asp
explains exactly how the figures are arrived at.

Although it would be clearer if they didn't fettle with the cars pre-test at least the results would be somewhat closer. Who drives with their alternator disconnected constantly?

http://www.theguardian.com/environment/2013/mar/14/car-manufacturers-manipulating-fuel-efficiency-tests

Strider590

OddballJamie wrote: »

Although it would be clearer if they didn't fettle with the cars pre-test at least the results would be somewhat closer. Who drives with their alternator disconnected constantly?

http://www.theguardian.com/environment/2013/mar/14/car-manufacturers-manipulating-fuel-efficiency-tests

Racing cars/bikes drivers/riders?

Total loss system.

sh0597

It's actually not difficult to calculate what your rough mpg will be.


I would like the EU to allow manufacturers to use a few more tests but it's done how it is currently because it's designed as a rough guide for non technical people. They have to do it like that or it would become a free for all.

sh0597

OddballJamie wrote: »

No, the worst offenders are Fiat with the Twinair and Ford's Ecoboost.

Both get around 60-70% of quoted figures.

It would be interesting to know if the CO2 levels are even accurate.

CO2 correlates with fuel consumption so if a car gets real world mpg of 66% then it's producing 50% more CO2.

FiremanDave

sh0597 wrote: »

CO2 correlates with fuel consumption so if a car gets real world mpg of 66% then it's producing 50% more CO2.

You've lost me can you explain that please?

AdrianC

The CO2 and consumption figures come from the exact same test. There is a fairly accurate correlation between the two - more carbon goes in, more carbon comes out - but it's not absolutely 1:1.