Is this the "50mpg under ideal laboratory conditions driven by an AI" or "as driven in a real city/highway by a human"?
Obviously, you can stomp on the throttle and get worse numbers if you want. But US MPG ratings are reasonably real-world accurate. (And the US fleet number comes from the same testing from the same group using the same metrics -- so they should be fair to compare)
As for MPG are you talking US gallons or imperial? Also what's your car's segment?
There are no cities with full bans on Euro III diesels or any diesel yet that I'm aware of or been denied entry in Sweden, and those few cities in Germany that do have them have only implemented partial restrictions.
The bans are not real, it's all just political maneuvering in order to get cheap votes.
I trust physics and chemistry, that's what I trust: when you elongate the exhaust manifold and manage to cool the exhaust down enough, you end up not even needing to inject Urea and still have an Euro VI compliant diesel.
It's the only company selling diesel passenger vehicles in Japan right now, with such a good motor that it's beloved by taxi drivers there. Which company is it, and what is the engine called?