Euro 7 standard: A quicker end for diesel?

The European Commission has hinted at the upcoming Euro 7 standard for passenger cars, first reported by Bild am Sonntag. Accordingly, emission requirements for nitrogen oxides could become so stringent that they would be very challenging to meet for diesel engines. According to BAMS from 15.11.2020, experts from across Europe in the "Advisory Group on Vehicle Emission Standards" have compiled a 66-page study and recommend that new cars should only emit 30 mg NOx per kilometer in the future, with a second version allowing only 10 mg/km. The limits are apparently intended to apply regardless of the combustion or propulsion principle. As described above, Euro 6 currently permits diesel engines to emit 80 mg/km and gasoline engines 60 mg/km. The limits should also be met not only at temperatures from minus 10 to plus 40 degrees but also at altitudes of 1000 or 2000 meters.

Tougher RDE cycle sets high hurdles

Additionally, the so-called "cold start bonus," which is still granted in the already stricter current RDE cycle and allows for higher emissions shortly after engine start, is to be eliminated. Therefore, self-igniting engines, like the pre-chamber versions from the past, would first need to "preheat." Electronics would also need to reduce performance repeatedly during peak loads, such as towing or fast highway driving, to stay within the permissible emission window. Generally, the problem would also persist on short trips. Alternatively, cars would need SCR systems like those common in trucks, with corresponding impacts on price. Diesel would simply become too expensive.

The impact is already visible today: According to an analysis by the CAR Institute at the University of Duisburg-Essen, only 27.2 percent of all new car orders in the EU-15, including Switzerland, featured diesel engines in the first nine months of the year.

VDA considers requirements unfeasible - EU Commission remains firm

According to VDA President Hildegard Müller, the new requirements are simply unachievable. "With the introduction of the planned EU-7 standard, the EU Commission will effectively ban combustion-engine cars from 2025," Müller told the German Press Agency. The Commission wants to mandate that a vehicle must remain "virtually emission-free" in every driving situation in the future – whether towing a trailer uphill or in slow city traffic. Müller believes this is technically impossible and "everyone knows it." EU Commission Vice-President and Climate Protection Commissioner Frans Timmermans counters, saying manufacturers could continue to use the technology as long as they meet the regulations.

The most expensive of two worlds: Diesel and Plug-in Hybrid

This would only be feasible through hybridization of the models, which combines two expensive technologies for diesel engines and currently only practiced by Daimler: Plug-in Hybrid Diesel. An exotic solution in terms of numbers: According to the Süddeutsche Zeitung, of 128,000 PHEVs in Germany, only 15,000 were combined with a diesel engine. Moreover, only 26.9 percent of diesel registrations were by private customers. In countries without diesel privileges like the UK or Switzerland, the diesel share is already quite marginalized to 16 and 23 percent, respectively.

What does this mean?

If what is now becoming apparent materializes and the Euro 7 requirements really come into force, the gap between electric vehicles and diesel engines would likely close. This would be good for the faster market adoption of electric vehicles. On the other hand, what the EU Commission is planning could prove to be a Pyrrhic victory. Instead of focusing too much on further reducing NOx, it would be better to see how we can reduce CO2 emissions faster, which have a more significant impact on the climate—without downplaying the health effects of nitrogen oxides.

However, diesel engines still have their place in certain applications, such as long-distance travel or carrying heavy loads like trailers or vans. Unfortunately, manufacturers have pushed diesel so far to the side with all the cheating that Rudolf Diesel’s pioneering idea is unlikely to make a comeback. But relying on plug-in hybrid turbo gasoline engines and selling them as "climate-friendly" is an illusion. Once again, it’s climate protection on paper, not in reality. This doesn’t protect the climate (actually, humanity) any better. There's no way around it: An honest CO2 tax and the abolition of pointless diesel privileges would be the fairest solution.