I'm as big fan of EVs as the next guy, and would love to see cities with clean air and no noise. But, there are few things that we forget about when we talk about zero-emmision cars.

EVs pollute less, but they pollute too, and in cities as well. They emit dust (including the most harmful particles: PM10 and PM2.5) from break discs and tires. Difference between CO2 in power plants and in city centers matters, but not that much. Once it's in the atmosphere the damage is done. As for NOx, the biggest offender in the dieselgate, Mazda's engines should not emit these.

Add a fact that in the current grid setup most of the energy is coming from coal, and that it's very unlikely it is going to change in a near future (mainly due to political reasons). Also, the waste from batteries is really ugly.

Given all that factors a 30% less polluting combustion engine is almost too good to be true. From a macro perspective the gain for environment is on par, if not better, than from electric cars.

My biggest problem is to believe in the numbers Mazda provides. Have to wait and see.