Mole

Im sure I read somewhere that emmissions were only read at a certain speed or at certain rpm, does anyone know if this is true? If it is this would be a total farse as a cars ecu could easily be designed to have a flat spot at this point then chuck out double the amount at 500 rpm later. Could anyone confirm exactly what they do to band a car for c02 emmissions?

GrittyShaker

Leave it out of gear and rev the nuts off it?

RISLAR

I'm sure that it is taken at 3000 rpms but they do rev it through the range to look for flat spots, they will even take a reading lower down if the readings to high

Dracoro

From what I've seen, there is almost a direct comparison between mpg and emissions.

However, this doesn't explain how a 30mpg S2000 gets a top band rating.

I would have thought the environmentals would prefer 2litre sports cars than 3.5 litre ones for example but hey ho.

Ultra_Nexus

Of course it's a farce!

Now that there is a target, manufacturers will aim for this number.

You will find that the new 17 litre Dogde Viper will produce 225g/km of CO2.

How else do you explain the new Porsche with it's >300bhp, 3.8 litre engine, in a 1400kg car producing the exact limit of 225g/km.

Porsche say it is the Direct injection technology.

I say it's a total bloody fiddle

No doubt it can do 50mpg too.

Dracoro

I think the next step for manufacturers is as follows:

Map car to have low amount of power (e.g. 100bhp). This will have a low emissions grading etc.

Then offer a "performance pack" mod that happens to be ok with warranty etc.

e.g. your 911 would have 100bhp out the box. Apply the mod (either from porsche, 3rd party or via a "secret" option in the trip computer etc.) and you're up tto 350bhp.

Mole

So is the reading taken over the rev reange then averaged out, taken between the normal running rev range of say 2000 - 6000 or at peak power out put.
Id really like to know because these muppets who make this law are wiping thousands off the value of second hand cars. Not only has jo public got to contend with the lates model comming out we now have the so called appeal of owning the lowest c02 emmitter.
Pretty soon cars will be like P.C's, redundant in just over a year.
I cant see how an s2k gets into band g?

Starlight

You need to ask Jonsey (Gareth) as he does this for his job.

If I remember, he said that they use special drivers who follow a pre determined (but varying) driving pattern on a rolling road.

Normal mortals are unable to match the patern and be smooth, etc.

Anyway he can tell you all about it