CO2 emmission for HDi

[tianorth]

When I bought my RCZ in June 2013 the tax was £130 per year group E (135 g/km)

Which is supported by Perrys technical spec (http://www.perrys.co.uk/car-news/tech-spec/peugeot-rcz-2-0-hdi-magnetic-2dr-coupe-tech-spec/)

Emissions

CO 0.362 - CO2 (g/km) 135 - HC N - HC+NOx 0.182 - Noise Level dB(A) 73.6 - NOx 0.153 -
Particles 0.001 - Standard Euro Emissions EURO 5

The peugeot website when you go to for price and spec brochure (http://www.peugeot.co.uk/media/peugeot-rcz-prices-and-specifications-brochure.pdf) - Page 7
It now states
EMISSIONS INFORMATION - Carbon dioxide (CO2) emissions (g/km) 19'' wheels - Euro 5 - 130.

Any idea of the changes?? Would it be ECU changes or engine changes?

As the road tax for the 130 g/km is £110 (group D - 121-130 g/km)

Can you get your tax grouping changed?

 

[Abzynthe]

I dont think you can get it changed as im sure it goes by the reported emissions when the car was manufactured.
I would say its most likely the new reported emissions would be down to the map in the ecu.