In 2015, in a case by ClientEarth, the UK government lost the legal argument that it had any effective plan to improve air quality in London and other cities, and then the Volkswagen scandal broke. What had been an academic discussion about how much pollution there was in a specific location became about whether diesels vehicles have been getting cleaner at all and can ever become truly clean.
While the UK and German governments helped water down the future EU real world testing regime in early 2016 by April both were forced to admit that that of 37 diesel Euro 6 cars they tested not a single one was within the legal limit when tested on the road and on average they emitted 600% more than permitted. That wasn’t the most significant thing about the announcement though. The announcement named the individual make, model and emissions for all 37 cars tested by the UK and German Governments over a 6 month period. This excellent summary from the Daily Mail presents it well and even has the dramatic chart from the report showing each car’s results in the lab as against its real world emissions. Until 2016 this would have been buried in an academic study with all names of vehicles and makers removed.
Almost at the same time Emissions Analytics published their Equa index of real world emissions of many best selling Euro 5 and Euro 6 cars. The tables work like a spreadsheet and are easy to use if you select show all. In essence a C rating means it would pass Euro 5 on the road. If it gets an A it really achieves the Euro 6 standard on the road and is therefore almost certainly not a diesel.
The public are now aware that what had been the Volkswagen scandal is now dieselgate. In March 2016 YouGov poll 69% answered yes (just 15% were against) when asked whether the most polluting vehicles should be charged more to drive in London. In Paris the mayor plans to ban all diesel cars by 2020.
The most thorough report to date by the think tank the Policy Exchange reviews the current situation in London and provides an in depth analysis of the policy options for the next mayor of London. Page 11 details how much worse diesel cars are than petrol in the real world for NO2. On average Euro 5 diesels emit nearly 20 times as much NO2 as a Euro 5 petrol car. On Euro 6, diesels average around 6 over the permitted limits while most Euro 6 petrol cars actually now achieve the lower limits they are allowed in the real world. For primary NO2 considered the most dangerous to health the Euro 5 diesels are 310 times higher than a petrol car. This is before particulates are considered which are also primarily a diesel issue.
In 12 months we’ve gone from
“the air is bad in many city roads but new diesel cars are much cleaner so the problem will soon be solved or maybe it’s the buses and lorries”
“some diesels may be bad but if I buy a Euro 6 it will be cleaner”
“I’ve just discovered my modern Euro 5 or 6 diesel has terrible emissions in the real world and so do all the others”
The stage is set for a shift from diesel at the very least in urban areas. While the motor industry will continue to try and shift its diesel cars it knows that further R & D in the area is likely to be uneconomic. Most cleanup options are not effective when most needed in urban environments and when used largely offset the efficiency and economic gains you would choose a diesel for.
The question for the industry, cities and drivers is how best to manage the transition to petrol, petrol hybrid and electric cars and when the tipping point will be reached. When it does there will be charges or bans on diesels in urban areas and second hand values for diesel cars are likely to fall sharply.