>http://www.bbc.com/news/science-environment-38170794
>
>I have not GOOGLed any of the history and my memory may be wrong (They say that the memory is the first thing to go. I would tell you what the second one is but I can't remember ;)) but IIRC, back in the 1990's weren't they touting diesel cars as the clean and fuel efficient alternative to petrol? It reminds me of Woody Allen's scene in Sleeper where the doctors are extolling the virtues of hot fudge and bacon....

There's a lot to like about diesels. They are more efficient, so when diesel fuel was much cheaper than petrol they were a lot cheaper to run. Fewer grams of CO2 per kilometer is, all other things being equal, environmentally friendly.

Many are capable of heavy-duty service, while no petrol engines are (with the possible exception of a few aviation motors).

Diesels can run on crappy fuel and long ago many did just that. A lot of early diesel powered cars richly deserved their Schtink-Wagen nicknames. Now road use requires low-sulphur fuel which costs more to refine and demand has risen so prices have too.

It's been known for a long time that diesels emit a lot of particulates, but recent research is showing how harmful they are. Now that reasonable alternatives such as hybrid or all-electric vehicles are available, smoggy cities can think about banning diesels.

Diesels will persist for a long time in heavy-duty applications such as trucking, marine, locomotive and stationary generation. But even with those there are alternatives on the horizon such as the Nikola class 8 semi-truck: http://arstechnica.com/cars/2016/12/nikola-hydrogen-fuel-cell-truck/