Channel 4 finds that real-world testing undermines "green" car claims
We have heard all about these European hypermilers who manage to churn out 45-50mpg U.S. in production cars, usually with high-technology turbocharged diesels. However, British TV station Channel 4's motoring website 4Car has carried out real-world fuel economy tests on eight low-emissions cars (5 diesels, 2 gasoline and one hybrid) and has found out that they didn't meet the official mileage and CO2 emission figures. Although the EU driving cycle is more theoretical than real-world driving, the difference is quite stunning. For instance, the worst offender was the Ford Focus Econetic, which got 11mpg Imperial (9mpg U. S. or almost 1l/100 km) worse in the Channel 4 tests than the official numbers whould have us believe. Moreover, higher fuel usage means that these cars pollute more than expected, and means they should fall in a different Vehicle Excess Duty (Road Tax) band and the driver should pay a higher rate. Follow us after the jump for the complete list and their press release which explains their evaluating method.
[Source: 4Car]
| Model | Official mpg (Imp/U. S./l*100km-1) |
Official CO2 (g/km) |
4Car observed mpg (Imp/U. S./l*100km-1) |
4Car observed CO2 (g/km) |
| VW Golf Bluemotion | 62.8 / 52.3 / 4.5 | 119 | 57.5 / 47.9 / 4.9 | 130 |
| Toyota Aygo | 61.4 / 51.1 / 4.6 | 109 | 54.5 / 45.4 / 5.2 | 122 |
| Fiat 500 1.2 | 55.4 / 46.1 / 5.1 | 119 | 46.5 / 38.7 / 6.1 | 142 |
| Skoda Fabia Greenline | 68.9 / 57.4 / 4.1 | 109 | 60 / 50.0 / 4.7 | 124 |
| BMW 118d | 62.8 / 52.3 / 4.5 | 119 | 53.5 / 44.5 / 5.3 | 139 |
| Honda Civic Hybrid | 61.4 / 51.1 / 4.6 | 109 | 50 / 41.6 / 5.6 | 133 |
| Mini Cooper D | 72.4 / 60.3 / 3.9 | 104 | 61 / 50.8 / 4.6 | 123 |
| Ford Focus Econetic | 65.6 / 56.6 / 4.3 | 115 | 54 / 45.0 / 5.2 | 138 |
Press release:
Real-world fuel tests undermine 'green' car claims
Current tests used by car makers to determine official fuel economy and carbon dioxide emissions don't provide accurate information for buyers, according to new tests carried out by Channel 4's motoring website 4Car.
4Car carried out real-world fuel economy tests on eight low-emissions cars and all failed to meet the official figures. Three cars were as much as 10mpg short of the published fuel consumption rates.
The tests examined the Golf Bluemotion, Skoda Fabia Greenline, Mini Cooper D, Honda Civic Hybrid, Toyota Aygo, Ford Focus Econetic, Fiat 500 1.2, BMW 118d, all of which are regarded as low emissions/fuel economy models.
The Golf Bluemotion got closest to its official figures in the 4Car tests, achieving 57.5mpg, only 5.3mpg short of the 62.8mpg return in the government-approved tests. Ford's special low-emission version of its best-selling Focus, the Econetic, returned 54mpg in the 4Car tests – 11.6mpg less than the official figure (see results below).
The fuel tests also revealed that claimed carbon dioxide emissions figures are unrealistic and that all the cars, which are currently in VED Road Tax Band B, should fall into Road Tax Band C.
The tests were carried out under strict conditions in order to achieve consistency. Unlike the official testing regime, which is carried out in a laboratory, 4Car's tests were conducted on the road to replicate 'real world' driving conditions. And unlike the official figures, which simply combine urban and extra urban cycles, 4Car carried out five sets of tests to arrive at an overall consumption figure (see Editor's notes).
4Car editor Tim Bowdler said: "The official test regime is too simplistic to embrace all the vagaries of real-world operating conditions and it allows certain types of car to look good – too good in fact.
"The batch of cars that we tested all claim to have 'green' credentials, but they are not as environmentally friendly or as economical as we've been led to believe.
"Manufacturers argue that the official tests offer a level playing field that enables potential car buyers to make direct comparisons, but they bear little relation to real-world driving. The official figures are misleading and I can't see manufacturers calling for a change because they know the current tests make their cars look more fuel-efficient and cleaner than they are."
Notes
All test cycles use corrected instrumentation, careful control of weight, simulated traffic halts and fixed rates of acceleration/deceleration, completely unaffected by other traffic. For example, the Urban Test is conducted on a virtually traffic-free route, takes 11.3 minutes, at an average speed of 17mph; it comprises 12 stops, plus three 'street corners' at 10mph, as well as brief period at 30-40 mph. The car is stationary for 180 seconds in total – 26.5% of the time.
Three modes – Suburban, Brisk and Gentle – include a cold start from a realistic (for the UK) 10degrees C. The routes are circular and the tests were not conducted in the wet or at significant wind speeds, with the car's air-conditioning and electrical consumers (heated screens, etc) off.
Our average or overall consumption is arrived at by combining 10% Urban, 15% Suburban and 25% each for the other three – Motorway, Brisk/out-of town and Gentle/rural driving.
Reader Comments (Page 1 of 1)
PeterG 3:58PM (8/14/2008)
So what? These numbers are known not to be real, they are known to be high. Not news.
Still averaging about 45mpg (US) real world. Still very, very good.
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why not the LS2LS7? 4:37PM (8/14/2008)
Well, 45 mi/gal perhaps isn't so impressive when you see how slow these cars are. People think they are getting a free lunch and they aren't, you have to make a sacrifice.
Also, you say it's not a big dea, but the Aygo was rated at 61.4 and got 54.5, while the Civic Hybrid ws rated at 61.4 and got 50. Wouldn't you think the customer would like to know the two cars don't have identical figures, but are 10% apart?
There are similar but not quite so extreme results with the VW Golf BlueMotion and the BMW 118d.
EVan 3:55PM (8/14/2008)
Yea.... let's rely on television channel employees for accurate automobile testing and evaluation.
Come on.
As long as the official numbers come from a standardized test that gives accurate direct comparisons between models then I'm happy.
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Wildgoosechase 2:18AM (8/16/2008)
So rather than target the attack at the real offender, which is the government for designing a useless test they target the automakers who have to pass the test. Kinda like blaming the victim.
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Scatter 4:43PM (8/14/2008)
Not entirely surprising that they got different results given that they weren't following the NEDC test cycle. But the main thing is that they always hold up low emission cars as failing the test but the same would apply to all cars. It's a big fat waste of time.
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Paul Sallmen 9:27PM (8/14/2008)
One has to realize that a government fuel economy test is a good frame of comparison. All cars tested are subjected to the exact same conditions. Of course real world fuel economy can vary, but for most vehicles, that variation should be, but not always, proportional to each model. However, I think this British outdoor test does draw attention to the fact that maybe vehicles tested should be subjected to harsher conditions. This where I think the American EPA (Environmental Protection Agency) was correct in re-evaluating the way they figured out fuel economy. I think people were frustrated by the fact that they were getting worse (and sometimes significantly) than official EPA figures. Quite correctly, the EPA now includes realistic driving conditions like cold weather, air conditioner use, above average highway speed and hard acceleration. That's one of the reasons why American EPA figures appear worse when compared to the EU combined cycle, Japan's 10-15 mode or Transport Canada's rating system.
That being said, I heard it's rather easy to beat EPA figures if you use simple gas saving techniques (like modest acceleration, coasting up to a traffic light, not going over 100 km/h (60 mph) etc).
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Chris 3:20AM (8/15/2008)
These Channel 4 employees are obviously lead footed!
I have owned a Nissan Primera 1.8 (petrol/gas) for 18 months now and I have been recording mileage since I got it. The official combined cycle mileage is 38 MPG (Imp). My recorded mileages: 40, 37, 41, 43, 44, 40, 41, 42...
The '37' was the result of driving to London and back at 90 MPH with the air-con on! Here in rural Somerset in mixed use I get excellent mileage for this class of car.
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Phil 3:47AM (8/15/2008)
4car are idiots.
First, they are bad at math. Since mpg is a reciprocal value, the biggest differnence in fuel usage is not the same as biggest difference in mpg.
Actually, using their figures, the Civic was furthest from its claimed consumption using 22.8% more fuel, NOT the Focus which used 21.4% more fuel. Just looking at the mpg difference (Civic was 11.4 mpg worse and Focus 11.6 mpg) isn't the same.
The tone of the article is heavily biased, implying that so-called eco cars fail badly in real life. However, they didn't test any non-eco cars to see if they are any better.
Wouldn't a car rated at 35 mpg offical not acheive 30 mpg in their test - a result similar to the 20% additional fuel consumed by the eco cars?
Finally, they admit that their test is not representative of your own personal driving conditions (% city, % highway, etc.). So actually they have just created another (possibly valid) standard test which each individual has to decide how relevant it is to them. Personally I get close to the EU average figures, so their figures are more relevant than the 4car test.
I would rather have a car that, in theory under controled conditions can acheive 72 UK mpg, then it's my task to get as close as possible in reality!
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Ernie 5:00PM (8/15/2008)
Congratulations channel 4, you just proved that lab tests and real world tests are not the same. Congratulations on publishing this stunning exposee.
But I'd be willing to bet that you'd see the same reductions in the real world tests if you tested other vehicles. Congratulations on your balanced reporting as well.
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Joe_thousandaire 6:17PM (8/15/2008)
This is telling us what we already know, the Civic Hybrid sucks and the Mini Cooper D is awesome.
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