-
It's to do with EU emissions requirements (I think). All bikes made after summer 2007 (I think) will be EURO3 compliant.
Other than general environmental consciousness its not that important right now.
But in 2020 (or maybe 2017 now) the ultra low emissions zone will be brought in so bikes will have to be EURO3 compliant or pay to drive through.
https://tfl.gov.uk/modes/driving/ultra-low-emission-zone
and
https://tfl.gov.uk/modes/driving/ultra-low-emission-zone#on-this-page-0
The zone is also likely (or hopefully) going to be extended to the North / South Circular.
Also if I'm going to keep the bike for a while then it seems to make more sense to have something that confirms to the most up-to-date regs - hence me seeing EURO4 compliance as a positive, albeit not a dealbreaker.
What's the score with this Euro3/4 thing?