At the end of July 2012 I purchased an approved used car. It was advertised online with a CO2 rating of 89g/km (I retained a screen grab of the advert). However the V5C that I've received shows a rating of 93 g/km.

In my mind this car has been mis-sold to me, so I'm considering approaching the dealer about it. However I'm uncertain if I should be truly concerned, because at 93 g/km the car still qualifies for zero road tax, and is London congestion charge exempt.

I'm not sure if I'm asking the right question, but please could you tell me if you're aware of any upcoming changes in CO2 tax thresholds that would place me at a disadvantage with the car at 93 g/km instead of 89 g/km? Any advice you can offer would be most appreciated.