OK, snark aside, looking back at that study, it is only one form of pollution they test and it is based on having a particulate filter that are known to clog in city driving conditions. They still emit 10x as much NOx as gas vehicles. I also wouldn't be all that surprised of this was another study faked by Volkswagon, or at least fooled by them since they probably did their tests on vehicles with defeat devices.
Hell, just reading the study I find disturbing flaws in their conclusions:
Quote:
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The grey line gives the time-integrated median of the distribution (i.e. from the test start to the denoted time, lower than the time-resolved ratio for much of the cycle due to the high absolute concentrations and low gasoline:diesel THC during the cold start, and below unity, indicating that total gasoline exhaust THC emissions are higher). Note the logarithmic scale in both panels. While THC emissions from diesel cars are up to one order of magnitude higher than gasoline emissions during almost the entire driving period, gasoline emissions are up to two orders of magnitudes higher when the catalyst is cold. Because of the cold start effect, integrated emissions from gasoline cars exceed diesel, even after a journey of several kilometres (~14 km). This effect is more pronounced at −7 °C (SI Fig. S3).
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Now, they mention a distance in km, but their chart shows time which is probably a much better indication of how people run their vehicles. After about 300 seconds(5 min) the warm gas is doing far better than the diesel. Sure, the -7 is worse, but I'd argue the majority of vehicles are driven above that anyway. And after 15 minutes it is basically a wash.
I also can't even figure out what vehicles/engines they ran these tests on, or how many they used. Was the sample representative? Who knows!
I did a bit of a search but didn't find any other study that shared their conclusions. So I'm gonna stand by way prior statement, that the study and its conclusions are bull####.
Anyway... stand on a hill for 10 minutes breathing the air while vehicles drive by, and try to convince yourself you can't instantly pick out the diesels as the roll by.