53% market share in Europe, 1% in the US – what's the reason for this discrepancy? Are diesel cars subsidized/privileged/politically supported here?
From the European Environment Agency:
"Diesel fuel contains more energy per litre than petrol and, coupled with the fact that diesel engines are more efficient than petrol engines, diesel cars have traditionally been more efficient to run ... producing less CO2 per kilometre driven.
In a number of countries, financial incentives have been used over the past decades to encourage the uptake of diesel vehicles.
However ... the efficiency gap ... has been decreasing in recent years. In 2014, the average new diesel car emitted ... only 2.5 g CO2/km less than the average petrol vehicle."
http://www.eea.europa.eu/publications/explaining-road-transport-emissions (pg 26)