Diesel witch hunt

[Velma's Dad]

I just did a bit of Googling about retrofits for Euro 5 (and maybe 4). Quite interesting I thought - but apologies to anyone for whom this is old news.

Looks like there are various prototypes of Selective Catalytic Reduction (SCR) systems around to bolt onto Euro 5 engines. They then have an Adblue tank (like a T6 Cali) and can comfortably meet Euro 6 standards. Fuel consumption suffers slightly.

The motor industry, especially the German manufacturers, have however been pushing for a software tweak, which is less effective in reducing emissions but obviously much cheaper than a hardware retrofit - and the pressure is on the manufacturers to cover the costs either way. Given the carmakers' preference for the software option, it's alleged that they've been over-stating the costs/problems of the hardware (ie SCR/Adblue) retrofit.

So while a lot of independent commentators - and the German motoring organisation ADAC - are saying a hardware retrofit might cost 1,500 to 2,000 euros, Daimler are saying no, 4,000 or more. Take your pick. I guess it depends on scale economies for a particular model.

If you have a 10 year old Polo diesel, you might not be interested in shelling out £2k (or £4k) on an upgrade to keep it in practical use. But for an otherwise perfectly sound and useable 10 year old Cali...?

Of course it all depends whether EU6 level diesels are given a long reprieve, maybe well past 2025/30, especially (paradoxically) if there aren't many of them on the road by then as most fleet replacements from here on are likely to be petrol - or indeed EVs.