I won't change my mind about emissions in NYC. NYC is full of modern, western cars.

Two-stroke engines are terrible, classic automobiles are terrible, cars with no emission regulations will tend to be terrible. Cars in NYC will have catalytic converters and other technologies to reduce tailpipe emissions.

The notable source of bad tailpipe emissions in NYC are heavy diesel trucks, which, to my understanding, produce a large proportion of tailpipe particulates (and NOx) in the US, despite being a small fraction of overall vehicles on the road. There are strong correlations with heavy truck traffic and asthma rates.

Unlike many other places in the United States, NYC area’s railroads are almost exclusively passenger rail and there is comparatively very little freight railroad traffic serving NYC and therefore there are way more trucks in NYC. They emit way dirtier emissions. The problem is never the cars; it’s always the trucks.

And oh also the small engines powering street food carts.

My bad. Your original post did not imply NYC nor did it exclude motorbike engines. It was very general.

western? what is this less polluting non-western car you are advocating?