Vorsprung durch cheatnik

I’ve avoided commenting on the whole VW scandal because A) I was busy and B) I was waiting for the other car makers to get caught out, as it would be unfair for us to focus on the one who got caught.

Figure 1, There's trouble in Wolfsburg

Figure 1, There’s trouble in Wolfsburg

Was I surprised by this story? No! Its been long established in the scientific literature that there is a large gap between how vehicles perform in lab tests on a rolling road and how they perform on the actual road in real world conditions. There’s a whole section of research into reconciling the differences between these two.

In part this gap is because real world driving conditions are quite variable. There’s a big difference between how a car performs in say stop go city traffic or on a motorway, or on a rural country road. Particularly when we throw in issues such as the weather conditions and driver behaviour (some people accelerate more aggressively and use the brakes more, others are more gentle, some break the speed limit, others don’t) and vehicle condition (e.g. the air pressure in the tire’s, oil, air filter, battery condition, loading, etc.).

Certainly, it has been long assumed that the car makers were optimising their vehicles to pass emissions tests and carbon dioxide limits. Which is a problem because beyond a certain tipping point reducing pollutants (Nox, CO, particulates, etc.) can conflict with reducing carbon emissions. Much like students swot up to pass an exam, the assumption was that the carmakers did likewise. However its all too likely that some crossed the line into outright cheating. The allegation is that the VW diesel’s could detect when they were being tested and set themselves up to reduce pollutants.

I would be very surprised as noted if VW was alone in this, while its not entirely my field, I have seen enough test data to guess that other manufacturers are pulling similar tricks. The BBC has an interesting bit of analysis they have performed on this and it does seem likely that this goes beyond a few diesel cars in the US.

But before we start ripping into the carmakers it is worth recognising that even when we factor in this “cheating”, cars have got a lot cleaner and a lot more fuel efficient over the last few decades. There is ample data to support that fact. However they are bound by legislation on the one hand and customer demand on the other. Inevitably they have to design on that basis.

Figure 2, Air pollution levels are generally falling in many cases, in this graph LA one of the America's most polluted cities [Source: Grantz and Shrestha (2005), http://californiaagriculture.ucanr.org/landingpage.cfm?article=ca.v059n02p137&fulltext=yes]

Figure 2, Air pollution levels are generally falling in many cases, in this graph LA one of the America’s most polluted cities [Source: Grantz and Shrestha (2005)]

Is this crisis likely the work of a handful of rough employee’s, as VW claim? I doubt it. In a modern car company no design changes get implemented without a nod from someone in management and some sort of paper trail. Certainly not a German company. If this is true, it imply’s that VW have very sloppy procedures and I sure as hell won’t be buying one of their cars, when I can get one from a better organised company in, say Italy or France.

Does this crisis mean its unethical to buy a diesel? I would argue no, it depends on what you do with the car. If you spend most of your time in stop go traffic in town, a petrol powered car will have lower pollution levels (although higher carbon emissions). However if you do a lot of country driving the situation is very different and you are probably justified in getting a car with lower carbon emissions and greater fuel economy. And of course arguing against someone buying a small diesel car is being “unethical” when you drive a massive petrol powered 4×4 is just plain silly.

Climate deniers would of course now claim that this push towards lowering carbon emissions has “cost lives”. Well not really. The problem has been that improving the fuel economy of vehicles is a bit like trying to make a silk purse out of sow’s ear. All forms of fossil fuels are dirty, they will generate pollutants, they will produce greenhouse gases. I’m all for trying to improve vehicle fuel economy, but these are measures that merely buy time. Ultimately we need to radically change how cars operate.

Switching to electric vehicles or fuel cell vehicles will help. However, that only works if the electricity grid is cleaned up and a carbon free source of hydrogen can be developed. Otherwise the gains are marginal. And I would argue for this reason, we need to think beyond simply changing what’s under the bonnet.

We need to make cars smaller too, as a small car will automatically use less fuel, regardless of how you choose to power it. Part of the problem is that many “size” their car on the basis of that once a year trip to France or the odd time they move a sofa, then spend the rest of the time driving around alone in a massive estate, complaining about petrol prices and how difficult it is to find a parking space. If instead they bought a smaller car, then hired a larger car (or a van) for that one time they need a larger vehicle, they’d be much better off.

This also leads to the concept of ditching the individually owned automobile altogether, which are then hired on a basis of need would mean less vehicles and allow the fixed costs of them to be spread amoung more people. An important consideration when you realise that the issue with alternatively fuelled vehicles is that they cost more to buy and maintain, although the running costs per mile (e.g. electricity or hydrogen) are much cheaper than with conventional vehicles.

Figure 3, Certainly it is strange the Americans making a big deal about “dangerous” European diesels, when guns are just fine!

Figure 3, Certainly it is strange the Americans making a big deal about “dangerous” European diesels, when guns are just fine!

So let’s not turn this crisis into an excuse for American car makers to bash a German one for the “crime” of stealing some market share from its Mexican built vehicles. Of course my fear is that this is exactly what will happen and the real issues will be ignored.


About daryan12

Engineer, expertise: Energy, Sustainablity, Computer Aided Engineering, Renewables technology
This entry was posted in cars, climate change, fossil fuels, politics and tagged , . Bookmark the permalink.

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