I’ve spent most of today talking about the VW dieselgate crisis on the BBC, starting at 5.30am on Wake up to Money and, as I write this, about to recommence shortly on BBC World News.

This is a story that is dominating headlines around the world, and which looks like it will continue doing so for some time yet.

Among the commentary however, there is a growing thread of what is, on current evidence, misguided opinion that if VW can get caught doing something so intrinsically dishonest that the entire car industry must be doing the same - not just with NOx testing, but in every form of what they do.

What bothers me is that VW’s fall from grace is being confused and used to tar an industry that has long stood at the vanguard of pioneering technical innovation, achieved through hard work, mega-bucks investment and inspiration rather than wilful cheating.

At present, this centres around those seeking to use the discrepancy between official fuel consumption figures and real-world fuel figures. John McIlroy has already offered up an opinion on exactly this point, stressing the key differences between a failed NOx test in the USA and claimed mpg figures in Europe. However, now the argument is raging, regardless of its relevance it needs addressing.