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Co/2 emissions - how are they measured?


Chav
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I might be wrong, but I believe average CO2 emissions are measured at the same time as fuel consumption is measured. i.e. figures are produced for urban, extra urban and mixed cycle. It's the mixed cycle figure that's used.

The problem is, this means the official CO2 figures for a car are just as accurate as fuel consumption figures are. i.e. not at all.

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And note that Darling's new bands are very narrow - some are 10g wide. I'd be willing to bet that the variability in real life is over 50g.

Which means that the tax you pay is just a random number. Which (a) makes it exceptionally unfair and (b) shows up the Chancellor as an idiot who doesn't know what he's talking about.

Suddenly, I understand why Darling fits so well into New Labour.

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No, the MoT emissions test is to check that the other emissions such as CO and NOx (i.e. those that actually pollute!) are within acceptable limits.

CO2 emissions for taxation purposes are set in the official tets when new and stay with the car for life, no matter how it is driven and how it is maintained. This works (after a fashion) if the CO2 bands are wide relative to the uncertainty inherent in the testing and use conditions, but that stopped being the case long ago.

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[ QUOTE ]

Yes there is, but you're taxed on the 'official' emissions figure for your model of car, not the accurate reading taken at MOT.

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....So, by the same reasoning, are a car's emissions changed by a remap and/or other performance mods?

[Cue for someone to say no, but that emissions are hugely increased by the addition of aftermarket LED DRL's !! grin.gif ]

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[ QUOTE ]

I might be wrong, but I believe average CO2 emissions are measured at the same time as fuel consumption is measured. i.e. figures are produced for urban, extra urban and mixed cycle. It's the mixed cycle figure that's used.

The problem is, this means the official CO2 figures for a car are just as accurate as fuel consumption figures are. i.e. not at all.

smashfreakB.gif

[/ QUOTE ]

Yes, using the New European Driving Cycle standard, as in the link I posted yesterday. It's a standard test pattern used in Europe for fuel economy and CO2 output figures.

To answer Robin's question, no a remap doesn't affect your official CO2 figures, but if you burn more fuel, you emit more CO2, so it does in reality.

So, what you need is a manufacturer to be brave enough to launch a 2 litre V6 that has been tuned for very low CO2 in that test pattern, then to 'accidentally' leak plans for a big sequential turbo upgrade kit that aftermarket companies (say, a fully-owned but 'independant' tuning house) could use to make aftermarket mods to said engine. grin.gif

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[ QUOTE ]

So, what you need is a manufacturer to be brave enough to launch a 2 litre V6 that has been tuned for very low CO2 in that test pattern, then to 'accidentally' leak plans for a big sequential turbo upgrade kit that aftermarket companies (say, a fully-owned but 'independant' tuning house) could use to make aftermarket mods to said engine. grin.gif

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It's only a matter of time. If you set silly rules, people will walk round them. coffee.gif

The 996-model 911 when fitted with the factory sports exhaust goes quiet from 29-31 mph for wholly inexplicable reasons. Some owners have learnt to fix a diode in place to prevent this.

On competely unrelated point, the EU noise regulations for new cars set a drive-by noise limit at 30mph...

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I remember when this whole CO2/road tax thing started, I was just looking for a new car for Mrs P. Brown had announced that there would be a nil rate band (I think) for small cars. For a moment I thought I was actually going to benefit from a Government idea. So I went out and looked for a small car that met Brown's definition.

There weren't any.

Feck it, I thought, and bought her a 1.6.

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