One way or another, the author was charged with writing a hit-piece on diesel passenger cars in order to put pressure on regulation to keep them out of the US m

One way or another, the author was charged with writing a hit-piece on diesel passenger cars in order to put pressure on regulation to keep them out of the US market. They did it poorly, with little factual backing. That's because they don't have much of a case. Clean diesel can be very clean. Clean gasoline engines are something we created in the 70's, 80's, and 90's; We used to have an enormous smog problem from tailpipe emissions, but we've basically solved it through regulation of what sort of fuel gets made and what sort of emissions controls are built into cars. With diesel trucks, we resolutely refused to make the corresponding changes for several decades; It's going to take 20+ years to get the truck fleet on the same footing as cars, and we only started the ULSD rollout about 10 years ago; we've only just begun major emissions level requirements in 2015 vehicles. The trucks you and I grew up around have no attempt to control emissions whatsoever, due to the power of US industry lobbyists. There is very little comparison to the clean diesels that are now a well-developed, highly regulated chunk of the EU passenger car market. The diesel emissions scandal was about a deliberate conspiracy within one manufacturer, wherein software was written to turn off major emissions controls in order to gain a very small mileage advantage, and then turn them back on to pass emissions testing. It has no relevance whatsoever to the practicality of clean diesel engines.