The Great MPG swindle..?
Discussion
After reading so many threads and articles regarding MPG I have a question.
Why are manufactures allowed to lie about the MPG that thier car can achieve?
Reason I ask is a friend of mine recently bought a Audi S3 very nice, very fast etc when I looked at the figures the official EU combined figure is 33.7mpg. My friend who has tried, can get 28mpg. Not a huge difference, granted but a difference.
I've heard of alot of people, driving allsorts of different cars who can't get anywhere near the 'Official EU' figures for thier car.
Are manafacturers giving specially adapted cars to the testing bods at the Eu, or are these EU people super advanced efficient drivers?
As MPG is a becoming a greater selling point for cars, are the car buying public ever going to question it? Or will it just be accepted you might get near, but never actually achieve the official MPG?
How have the PH massive found thier real MPG compared to the Mananfacturer/EU MPG?
Why are manufactures allowed to lie about the MPG that thier car can achieve?
Reason I ask is a friend of mine recently bought a Audi S3 very nice, very fast etc when I looked at the figures the official EU combined figure is 33.7mpg. My friend who has tried, can get 28mpg. Not a huge difference, granted but a difference.
I've heard of alot of people, driving allsorts of different cars who can't get anywhere near the 'Official EU' figures for thier car.
Are manafacturers giving specially adapted cars to the testing bods at the Eu, or are these EU people super advanced efficient drivers?
As MPG is a becoming a greater selling point for cars, are the car buying public ever going to question it? Or will it just be accepted you might get near, but never actually achieve the official MPG?
How have the PH massive found thier real MPG compared to the Mananfacturer/EU MPG?
They aren't lieing. All cars sit the same test, they get their respective scores. The car will achieve the claimed MPG, if it goes through the standardised test cycle. Unforuntatly, professional drivers skilled at achieving optimal MPG are few and far between (in the real world), similarly, the exact circumstances of the test are rarely replicated (in the real world)
What Car have launched a real world MPG test in response to this issue. The problem is that official MPG figures are gathered using a set test which makes it very easy to tune a car to perform well in. The test also involves periods of being 'stationary' which means a car with stop-start uses no fuel at all for some of it.
However, before you start saying the test should be changed, it's the same test used to calculate CO2 emissions, and therefore decide how much tax you pay. Everyone knows it's nonsense and produces pie-in-the-sky figures, but it allows you to have a BMW 5 series and only pay £30 a year in road tax so it's not all bad!
However, before you start saying the test should be changed, it's the same test used to calculate CO2 emissions, and therefore decide how much tax you pay. Everyone knows it's nonsense and produces pie-in-the-sky figures, but it allows you to have a BMW 5 series and only pay £30 a year in road tax so it's not all bad!
The test is highly unrepresentative of real driving but what are we meant to do about it now? To change the test to something more representative would make it impossible to compare cars tested on the old test to those on the new, it would push cars up into higher tax bands and make it even harder for manufacturers to meet the arbitrary CO2 requirements that they've been given.
The biggest problem to my mind, is that the test seems to flatter turbocharged engines and automatic gearboxes more than N/A engines and manuals, pushing the whole industry in a direction that I personally would prefer to not see it go.
The biggest problem to my mind, is that the test seems to flatter turbocharged engines and automatic gearboxes more than N/A engines and manuals, pushing the whole industry in a direction that I personally would prefer to not see it go.
I wouldn't say it flatters auto gearboxes at all, only DSG automated manual type boxes. The main problem is that the car is driven far more gently in the tests than in most real world situations, which is why I'm yet to meet anyone, punter or journo, who can get a Fiat 500 TwinAir within 20mpg of the published figures!
BettySwollocks2 said:
5 mpg or so difference isnt too bad, but my fabia VRS has an urban mpg figure of 36 or so and in the town I will struggle to get about 23/24.
A friend of mine has a remapped Ibiza Fr (same engine, v similar weight) he averages 49mpg from his in general driving.Basically what I'm saying is. You drive like s
t (economy wise)You might (or might not
) find this interesting
http://www.ecotest.eu/html/3a_EcoTest%20Testprozed...
(for even more details see http://www.ecotest.eu/html/Testing%20and%20Assessm... )
It clearly shows how much of a difference stop-start can make with the amount of zero mph sections.
Also bear in mind that the acceleration is set to lowest common denominator, in the real world you'd put your foot down to get up to speed, in the test they crawl up to speed, the fastest cars taking the same time as the slowest (which obviously has bearing on the mpg).
Personally I'd like to see it with all acceleration full throttle and eliminate the stop's from the mpg and CO2 calculation (but manufacturers allowed to then use them for promotional purposes).
) find this interestinghttp://www.ecotest.eu/html/3a_EcoTest%20Testprozed...
(for even more details see http://www.ecotest.eu/html/Testing%20and%20Assessm... )
It clearly shows how much of a difference stop-start can make with the amount of zero mph sections.
Also bear in mind that the acceleration is set to lowest common denominator, in the real world you'd put your foot down to get up to speed, in the test they crawl up to speed, the fastest cars taking the same time as the slowest (which obviously has bearing on the mpg).
Personally I'd like to see it with all acceleration full throttle and eliminate the stop's from the mpg and CO2 calculation (but manufacturers allowed to then use them for promotional purposes).
davepoth said:
Where they're directly comparable, the US EPA numbers are much more realistic.
^ ThisBut dont forget to convert from US Gallons to Imperial Gallons, but the figures actually are really quite good and more based in the real world than anything else I have seen.
For the EU ones, its done on a test bed in closed conditions and its easy to spoof. Rumours been going around that some of the manufacturers have a secret programme on the ECU that recognises when its on the test bed and goes into super-eco mode for maximum economy. And of course the burn rates / ratios for the fuel are calibrated to maximise MPG for certain speeds, gear changes etc.
Its a bit of a con and the combined figure is a bit of miss for most people anyway.
BettySwollocks2 said:
5 mpg or so difference isnt too bad
That depends.Taken from Wikipedia:
"If a driver who travels 15,000 miles (24,000 km) a year switches from a vehicle with 10 mpg to 12 mpg average fuel economy (0.10 gallons per mile to 0.083 gallons per mile), 250 gallons are saved. A similar 20% improvement in exchanging a 30 mpg for a 36 mpg (0.033 gallons per mile for 0.027) vehicle saves only 83 gallons."
StottyZr said:
A friend of mine has a remapped Ibiza Fr (same engine, v similar weight) he averages 49mpg from his in general driving.
Basically what I'm saying is. You drive like st (economy wise)
If your friend has the Mk2 1.4TSI then I'd say his driving is the issue! If we're talking Mk1 1.9TDIs then 49mpg is pretty average.Basically what I'm saying is. You drive like s
t (economy wise)I actually measured my MPG this morning (I only do it about once per year) and I've averaged 29.2 over the last tank which has been my normal commute. I've just found out the official figure is 28.2 so I'm beating it without trying
My opinion is that cars designed in the last 6 years (or so) have been designed around the test too much. It wouldn't surprise me if the engine management software was able to detect the first 30 seconds of an official test cycle and drop the car into a more economical map for the rest of the test.
My opinion is that cars designed in the last 6 years (or so) have been designed around the test too much. It wouldn't surprise me if the engine management software was able to detect the first 30 seconds of an official test cycle and drop the car into a more economical map for the rest of the test.
Fastdruid said:
You might (or might not) find this interesting
http://www.ecotest.eu/html/3a_EcoTest%20Testprozed...
(for even more details see http://www.ecotest.eu/html/Testing%20and%20Assessm... )
It clearly shows how much of a difference stop-start can make with the amount of zero mph sections.
Interesting link, ) find this interestinghttp://www.ecotest.eu/html/3a_EcoTest%20Testprozed...
(for even more details see http://www.ecotest.eu/html/Testing%20and%20Assessm... )
It clearly shows how much of a difference stop-start can make with the amount of zero mph sections.
I always wondered how stop-start made such a massive difference, I know now!. I bet it doesn't make that much difference in real life unless you live in a major city?Intesting to see the motorway test too.
MPG tends to improve a lot too as engines loosen up, lots of tests of 'real world' mpg are done with demonstrators with under 20k on the clock.
On the other hand, quoted mpg and attainable mpg certainly differ on most cars. Small displacement turbo engines are the worst culprits from my experience.
On the other hand, quoted mpg and attainable mpg certainly differ on most cars. Small displacement turbo engines are the worst culprits from my experience.
Bought the wife a new car in Sept gone and MPG was a big factor in buying a new car as her old car was a petrol freelander and was returning 23mpg.
The car she picked is suppossed to get 64.2 and since then I have not seen it over 40mpg.
I know, I know she is just running around the town and has yet to do a long run, but it does bug me a wee bit.
The car she picked is suppossed to get 64.2 and since then I have not seen it over 40mpg.
I know, I know she is just running around the town and has yet to do a long run, but it does bug me a wee bit.
FisiP1 said:
MPG tends to improve a lot too as engines loosen up, lots of tests of 'real world' mpg are done with demonstrators with under 20k on the clock.
On the other hand, quoted mpg and attainable mpg certainly differ on most cars. Small displacement turbo engines are the worst culprits from my experience.
Yep, I'm willing to bet the tests manage to all get done 'off-boost', of course when you drive them you use more than 1mm of the throttle and *bam* there goes your mpg. On the other hand, quoted mpg and attainable mpg certainly differ on most cars. Small displacement turbo engines are the worst culprits from my experience.
Bit like the way the twin-air 'swindles' the tests, built to get low CO2 figures, but drinks like a fish when you drive it like it wants to be driven.
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