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Comment by padelt | Hacker News Reader

> Europe was really led astray when they were told that diesels were better for the environment

Were we led astray? Or are we discussing the last few percentages beyond an actual advantage over gasoline engines?

http://www.theguardian.com/environment/2015/sep/24/uk-france...

The reason air pollution is so much worse in European cities than American ones is largely due to diesel passenger vehicles.

That both suprises me, do you have any sources? Honest question, both seem counterintuitive. Maybe I am actually fed enough "feelgood" information in the past.

http://www.theguardian.com/environment/2015/mar/05/industry-...

That is an article from greenpeace about poor EU environmental standards in power stations. Sure it is bad but, it does not compare air pollution in EU vs US cities or attribute anything to cars.

See for example Paris's recent (yesterday?) "no car day" in the center. The city's usual blanket of smog is gone. France of course having the highest %age of diesel cars in its passenger fleet of any country.

Paris is one of the densest cities in the world[1], placed 6th if you disregard cities with a population of less than a million. It's the most dense large city among G8 countries. The only vaguely comparable European cities are Athens and Barcelona, both smaller and less dense. London has about a quarter of the density of Paris. The most dense large German cities, Munich and Berlin, less than a quarter. The city I live in -- part of one of the world's largest conurbations --, less than a tenth.

Statistics like these should be taken with a grain of salt (for one thing, city delimitations are fairly arbitrary), but the details are not worth haggling about: the point is that Paris is not at all representative of large European cities.

[1] if Wikipedia can be trusted on this https://en.wikipedia.org/wiki/List_of_cities_by_population_d...

Some air pollution data here:

http://www.nasa.gov/topics/earth/features/health-sapping.htm...

That goes against my subjective experience. The contribution of buses and trucks in US cities is also significant, and my sense is that EU regs on those vehicles are more stringent than US. I particularly tend to notice how much -noisier- large US vehicles are than European equivalents in a city traffic environment, which tends to correlate with lower efficiency.

Europe generally has more stringent regulation and worse pollution than the US. It's many more people in a smaller space.

Noise isn't a good predictor though, a muffler is a drain on efficiency.

Actually the VWs that were emitting 40x pollution in the US were only 10x of the Euro regs.

Eu has stricter PM limits, the US has stricter NOx limits.

http://www.hybridcars.com/will-america-avoid-europes-clean-d...

Also because US cities are much more sprawled, and are often organized in neat, efficient grids instead of having formed organically over the course of ~2300 years. Compare maps of Paris with any US city.

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