Sustainable Energy Ireland has a useful energy emissions calculator for all models of car purchased since 2000. I tried this out for my 2003 Renault Scenic and was quite shocked at how poor the emissions were (173 gC02/km) and that it could cost €600 under the new motor taxation scheme, compared to €292 under the current scheme. Fortunately, it will not cost this since it was registered prior to July 2008 and is thus exempt from the new system.
I was also very surprised to see how little by comparison a brand new 2008 BMW 520 Diesel is going to cost under the new scheme (€290 compared to €689 under the current scheme). This car is very efficient and emits a mere 149 gCO2/km.
The times they are a’ changin’