What was once hailed as the most ecofriendly power system and heavily promoted by the UK government as such, the diesel has now acquired a bad name. The Volkswagen Dieselgate scandal hasn't helped, but the main reason for its fall from grace is that although CO2 emissions are lower (great for climate change), diesel also pumps out harmful particulates (bad for people). The growth of electric cars obviously poses a threat to both diesel and petrol-driven cars, and there has been talk of banning all diesel and petrol cars by 2040. Campaigners want that ban brought forward.
Another piece of EU law coming into effect adds another worry for diesel drivers. If the car fails to meet Euro 6 emissions regulations, as from April 2019 drivers of such a vehicle will have to pay £12.50 a day to drive in London's Ultra Low Emissions Zone, on top of the congestion charge. Thankfully this will mainly apply to older cars, but it is a thought to conjure with.
In the meantime drivers doing a fair number of miles will benefit from the higher mpg of modern diesel cars, with high performance to match. The age of the diesel is far from over.