As if we didn't know.
www.bbc.co.uk/news/business-21759258
"Slick tyres are pumped hard to reduce rolling resistance. Brakes are adjusted, or at times even disconnected, to reduce friction. Cracks between body panels and windows are taped up to reduce air resistance. Sometimes they even remove the wing mirrors."
"The book of tricks available to carmakers during the tests includes techniques such as:
disconnecting the alternator, thus no energy is used to recharge the battery during the test
the use of special lubricants that are not used in production cars, in order to reduce friction"
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>> Sometimes they even remove the wing mirrors.
Grrrr!!
Last edited by: VxFan on Thu 14 Mar 13 at 13:59
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What a load of rubbish-the tests which are government observed MUST be carried out on tyres that are 30-50% worn-ie. not new or slicks and at an appropriate pressure to stop undue deflection on the rollers-usual pressure is 30psi/2 bar.It may be higher if the rollers are very small in diameter but this type of dynamometer is not common in the EU.It is a legal requirement that the air con/heater is off and that the load setting for the dynamometer is checked both on the dynamometer and on the road.It is also a legal requirement that the vehicle may be tested on the road by the government testing authority to ensure it drives normally,both hot and cold.
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As I understand the tests, they are carried out by manufacturers in their own facilities. It may be that EU or state government observers could attend but I wasn't aware that they did. Hence the "resetting" of parameters such as hybrid battery discharge level, leading to ludicrously optimistic results. A 3 litre Lexus barn-door replica would get terrific mpg figures if the engine was hardly called upon.....
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The tests may be carried out at manufacturers facilities but will be observed by government appointed testers who produce an official report complete with their official stamp;tests may be carried out at any approved laboratory-some are manufacturers,some actual government ones and some neutral but all must be officially approved before use for actual testing.
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The ICCT report can be downloaded (pdf) from this link: tinyurl.com/aha8gwx
Seems to be a lot of scope for fiddling in the current scheme. I often wondered why Honda were unable to match other makers in the CO2 bragging rights!
Last edited by: NIL on Thu 14 Mar 13 at 16:55
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>>>> Sometimes they even remove the wing mirrors.
Just found a new job for Mrs Humph..........
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"Grrrr!!"
You'll have to face the logic one day, VxF, wings are about halfway along a bird, mirrors are about halfway along a car - therefore they can sensibly be referred to as 'wing-mirrors'. ;-)
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Yes. The last sentence or two in this post;
www.car4play.com/forum/post/index.htm?t=10434&m=232866&v=e
was hinting at the practices mentioned in the report.
Optimising performance during test and flexing the rules as far as they can go has been a long standing feature of vehicle testing.
So, yes, there are some aspects of the test procedures which need to be tightened up, and better controlled - but, the underlying principle of the test is sound.
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Yes. And I understand the new incumbent at the Vatican is a Catholic.
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I wonder what the rules are on the fuel? Petrol without ethanol will give more power and more economy too.
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Why is anybody bothered by this revelation anyway?
Nearly all of us on this forum knew mpg figures were way off real life figures and almost unachievable unless we all drove at 40mph everywhere. Its all 'traders puff' at the end of the day.
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"Why is anybody bothered by this revelation anyway?
Nearly all of us on this forum knew mpg figures were way off real life figures and almost unachievable unless we all drove at 40mph everywhere"
Quite. And if CO2 figures are reduced, doesn't it mean we pay less tax?
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>> Why is anybody bothered by this revelation anyway?
Because HMRC (and some employers) use the theoretically achievable fuel economy obtained in these tests (somehow averaged across manufacturers and engine sizes) as the basis for the mileage rates which they allow/pay.
Means that there are conceivably circumstances in which an employer's mileage rate does not fully reimburse the actual cost of fuel used whilst pointing (rightly or wrongly) to HMRC as the reason for this.
So, I guess some people might be bothered ?
Last edited by: idle_chatterer on Fri 15 Mar 13 at 00:35
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I long to try a Fiat Twin-Air. My ambition is to get it to do 20mpg or less by making it go fast. Not all the time of course, just to see if it's possible.
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No need to go fast - just go everywhere at 35mph.
In first gear.
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>> just go everywhere at 35mph.
>> In first gear.
That would be cheating. I just mean by going as fast as possible.
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All tests are manipulated.
If they really wanted unmanipulated tests they would buy 100 new cars anonymously and then test them on the road, like weights and measures inspectors do.
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If we assume all manufacturers manipulate the tests then it will all tend to balance out as long as you simply use the the tests to establish relative rather than absolute economy.
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I defy anyone to get the book combined figure from my V60. No doubt in my mind that the test was "compromised"
The C5 had the same engine yet claimed almost 10 mpg less and got pretty close to the book figure. My journey home from work has a fairly long downhill run and if you reset the computer on it would read 10 - 20 mpg over the bookfigure, but in the Volvo its still 5 - 10 short.
On this basis I can only conclude that its impossible to achieve the combined figure
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>> I defy anyone to get the book combined figure from my V60. No doubt in
>> my mind that the test was "compromised"
>>
>> The C5 had the same engine yet claimed almost 10 mpg less and got pretty
>> close to the book figure. My journey home from work has a fairly long downhill
>> run and if you reset the computer on it would read 10 - 20 mpg
>> over the bookfigure, but in the Volvo its still 5 - 10 short.
>>
>> On this basis I can only conclude that its impossible to achieve the combined figure
>>
It's massively temperature dependent, by as much as 10-15% in a diesel. The tests are done inside in a nice, warm cosy room.
Mind you, HJ raves about his 320d (wonder how much BMW are paying him?) and its ability to actually hit the book figure. I'm inclined to be skeptical, since my 120d used to miss the target by a country mile and the best I ever got out of it was 51mpg on the motorway at 56mph, and it was the most boring journey I've ever done.
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>> Mind you, HJ raves about his 320d (wonder how much BMW are paying him?)
>>
I am afraid I have become very disillusioned with HJ.
8< snip comment removed
However, I still find his Saturday piece an interesting read.
Last edited by: VxFan on Sat 16 Mar 13 at 17:42
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So you admit have no evidence but are prepared to make a potentially libellous statement on the forum. Good luck.
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A colleague reports that by attaching a roof box and two surfboards to a Prius, loading the box and the car to the gunwales and then thrashing the living doodahs off it all the way to the south of France you can get one to do 35 mpg.
Ah, the valuable research that can be done with a company fuel card......
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I couldn't give a monkey's about quoted emission levels. When I'm choosing my next car I don't even look at the emission figures.
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>> I couldn't give a monkey's about quoted emission levels. When I'm choosing my next car
>> I don't even look at the emission figures.
Do you look at the tax band?
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>>
>> Do you look at the tax band?
>>
I'd have thought that this was actually a very small percentage of the running costs of a private new or newish car given the sizable amount of depreciation over the first few years ?
My own experience (as I've said too many times before) was that my BMW 330d did achieve something like its claimed economy whereas my last Audi A4 didn't by a margin approaching 20%. Our current Golf VI 160PS 'twincharger' DSG does pretty well and certainly achieves something like its claimed economy on a run. It's probably OK round town too (albeit behind the claimed figures) but then it prefers 98RON which is thankfully not prohibitively expensive in Aus, would be more painful in the UK I suspect.
I still have a suspicion that under powered cars (of the Drive-e, econetic, Bluemotion etc varieties) do rather better in artificial testing than in the real world where they're being worked hard to get decent performance?
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>> >> I couldn't give a monkey's about quoted emission levels. When I'm choosing my next
>> car
>> >> I don't even look at the emission figures.
>>
>> Do you look at the tax band?
>>
I glance at it, but only out of curiosity. It doesn't influence my choice one iota. VED is a minor part of the running costs of a car.
Last edited by: L'escargot on Mon 18 Mar 13 at 10:40
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The trouble car makers have is peoples driving styles are so different. So if they gave the same car to 100 people with a test route, they would get 100 different figures.
The problem is that the test is unrealistic to modern driving anyway. Once you go above the 56mph then you are already going to lessen the achievable figures.
An easy mod would be to have the urban, extra urban and combined, but also have an efficiency figure for cruising at 70, on flat road with no headwind. That at least should be easy to test!
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>> I glance at it, but only out of curiosity. It doesn't influence my choice one
>> iota. VED is a minor part of the running costs of a car.
you have been so long choosing your car, I would be looking at how well it performs on the next ice age dinosaur avoidance swerve test.....
Last edited by: VxFan on Mon 18 Mar 13 at 12:44
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>> >> I glance at it, but only out of curiosity. It doesn't influence my choice
>> one
>> >> iota. VED is a minor part of the running costs of a car.
>>
>> you have been so long choosing your car, I would be looking at how well
>> it performs on the next ice age dinosaur avoidance swerve test.....
>>
Or the Focus will be eligible for classic car insurance
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Of course, you could have accurate CO2 and fuel economy figures but then pay through the nose on the VED and company car tax if applicable.
The Insignia technically qualifies for the £30 tax, but given that you're supposed to use a can-o-gunk spare tyre I suspect a porky sales rep with a takeaway coffee probably pushes it over the 115g/km limit.
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'Carmakers manipulate emissions tests' - VxFan
