Are we witnessing the death of the diesel engine?

Shaun McCarthy
30 September 2015

The facts about Volkswagen’s apparent manipulation of US emissions tests will doubtless unfold in the coming weeks and months, but I would like to share some thoughts on the wider issues this brings into play.

There is already a misconception this is all about fuel consumption and carbon dioxide emissions. It is not, it is about air quality. Nitrous oxide and particulate matter impact human health, particularly in cities. There is good evidence that 40,000 people die prematurely in the UK due to these emissions, and diesel engines are a significant source of this type of emission. Carbon dioxide emissions are a greenhouse gas and a primary source of global warming which is giving rise to catastrophic climate change. You are unlikely to die of CO2 emissions, but the human race may do in a few generations.

Governments around the world have responded in various ways to limit CO2 emissions, including “cleaner” cars with lower fuel consumption, many of which were diesel. This led to most car makers investing heavily during the 1990s in diesel engine technology which is more fuel efficient but much worse for local air quality. Renault and Citroen were encouraged to lead the way supported by lower excise duty in France and other mainland European countries, making diesel a cheaper fuel to buy. In the UK, company car tax and road tax were based on CO2 emissions, again making diesel a good idea.

When the air quality problem was discovered, legislation was introduced to try to clean up the diesel engine. In the EU, regulations related to category four and five engines failed to resolve the problem. The new category six is supposed to be more stringent but does it place requirements so stringent that the only way is to cheat? It is worth noting EU regulations require “in use” testing, where as US regulations do not. It is not clear yet whether the EU rules have been circumvented as well.

Remember Gerald Ratner? His company famously died when he joked that one of his products was “total crap”. Customer trust had been lost at a stroke. Will Volkswagen suffer the same fate?

Does this also herald the death of the diesel engine in cars? Continuing to support technology that is demonstrated to be bad for our health seems a bad idea at the moment. Will this accelerate the already growing market for electric and hydrogen powered vehicles? Only time will tell.

Shaun McCarthy is director of Action Sustainability

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