Keeping It Green


Governments, well what can I say? They tell you one thing one day and then they tell you something completely different the next. Yesterday we were going to bomb the Syrian Government – today we’re going to bomb their opposition. Yesterday we were told to buy Diesels and save the planet and today - well, just ask Volkswagon.


It’s not every day that a world famous brand (inspired by Adolf Hitler incidentally) shoots itself in the foot quite so spectacularly. And I’ll bet a few million VW owners will be feeling a bit wobbly as we wait for the next instalment.




But what have VW actually done that’s so terrible?


It rather looks to me as if they’ve just given their customers what they want.




We want a car with good performance – check


We want a car with good fuel economy – check


We want a car that passes the latest emissions tests – check


We want to benefit from tax breaks linked to the above tests -check




Ok, they sort of cheated on the tests, but you still got what you paid for.


Do you get the broadband speed you paid for?


Do you think you’ll get the pension you paid for?




The difficulty is that when governments require products (cars, fridges or whatever)  to be subjected to testing then the products will be designed to pass that test. If the test is conducted in a laboratory then the product will be designed to pass the test in a laboratory. If you want it to pass the test in normal driving conditions you have to conduct the test in normal driving conditions.   




So why are the Americans making such a fuss?


The issue concerns two different pollutants produced by diesel engines. One is CO2 or carbon emissions (greenhouse gas which causes global warming – although the globe is cooling at the moment but let’s not go there today,) and the other is NOX or nitrogen oxides (which create smog and make you cough.)


In Europe we focus on CO2 because we care about polar bears in the next century. In America they focus on NOX because they don’t like smog. And this is where VW has tripped up.


Common sense suggests that the Americans might have a point. Global warming (or global cooling) may (or may not) be linked to human activity. But we can’t predict a storm at the weekend let alone what the climate will be like in a hundred years time. However, we do know that if you pump enough NOX into the atmosphere it will make the air dirty – and it will make it dirty today.


So Volkswagon are the bad guys then?


Not exactly. You see, most of the NOX in the air comes from power generation and industrial processes. The NOX which does come from motor vehicles comes largely from commercial trucks and buses and older, less efficient diesel cars.  So, to look at the bigger picture, the havoc wreaked by VW is pretty infinitesimal.


Of course, if you are a bit of a cynic you will have noticed that American car manufacturers produce very few diesel engined cars and the ones they do make aren’t very good. Maybe they don’t want what’s left of their motor industry decimated by the Germans?


So, is it the end of the road for VW? Of course not, the Germans (who run Europe) will not legislate their biggest car manufacturer into oblivion. Tests show that no other manufacturers seem able to make cars which meet the latest emission regulations in normal driving conditions, they just haven’t been caught fiddling the figures. The EU have already decided to relax the emission targets for next year to give the diesel car manufacturers a chance to achieve them legitimately.   


But what about the whole concept of the diesel engined car, could it be the beginning of the end?


I shouldn’t think so, or not for a long time yet anyway. Petrol as a fuel is less efficient than diesel. Electric cars are a niche product with sales driven largely by tax incentives.


Efficient, economical, powerful and practical, that’s diesel, and as we know, the public tend to vote with their wallets.




NB If anyone with a degree in physics is reading this, I know I have rather over simplified the science of exhaust emissions. I think I still have a point though.