THE BATTLE BETWEEN FUEL ECONOMY AND EMISSIONS

The EU has arguably long been playing catch-up in terms of tailpipe pollution regulations, having been more concerned with fuel economy. The US, led by California, has been doing the opposite.

Californian pollution laws arrived in 1975, but the Euro 1 pollution regulations didn’t come into effect until 1992. By today’s standards, they were pretty lax, but they did result in the introduction of catalytic convertors and unleaded petrol, albeit 17 years behind California.

Euro 2 arrived in 1996, but the main effect was a big reduction in the generous allowance for CO levels.

In truth, the EU was more interested in reducing CO2, and after the Kyoto Protocol, it required car makers to lower the average CO2 output of their new car fleet by around 4g/km (or 2%) per year between 1998 and 2009.

In 2009, the UK introduced a new tax regime to further push new car buyers into “low-co2” diesels.

In retrospect, it obviously made sense for European car makers to prioritise diesel to improve economy while not having to worry too much about pollution under EU laws.

Indeed, when Euro 5 arrived for all new diesel cars from 2013, the NOX limits were 0.06g/km for petrol engines but 0.18g/km for diesel ones – a level three times higher.

Volkswagen infamously transgressed the EU-US pollution divide by selling frugal diesel engines without Nox-cutting Adblue injection in the US. But US pollution rules allow for new cars to be selected randomly and tested in the real world, which is how Volkswagen was caught.

After Dieselgate broke in the US, the EU investigated

Euro 5 diesel engines, claiming to find cheat software

(the engine management recognising when a lab test was being carried out) and accused car makers of gaming the system by using shutdown devices that allowed increased pollution at certain ambient temperatures.

Ironically, the much more rigorous Euro 6 rules (which cut NOX levels for diesels to 0.08g/km) arrived in the very same month as Dieselgate. But the EU’S lab-based testing regime was now entirely discredited, so just two years later, in September 2017, the RDE (Real Driving Emissions) pollution and economy tests were introduced.

The hyper-strict pollution proposals for Euro 7 could therefore be seen as a direct reaction to Dieselgate and the EU finally outlegislating even

California.