Euro VI and beyond: What next for the mission to eliminate transport sector pollutants? 

The quality of fuel burnt by road transport vehicles is one of the primary factors determining the amount and types of pollution they produce. Since 1992, best-practice fuel standards have been gradually shifting toward cleaner formulations, which when combined with vehicle technology upgrades, have resulted in major reductions in pollutant emissions from vehicles, particularly heavy-duty diesel vehicles like trucks and buses.  

Black carbon, a form of fine particulate matter PM2.5 is one of the primary pollutants affected by the quality of fuel. Black carbon is also one of the most important short-lived climate pollutants that can be reduced to meaningfully slow down the rate of global warming, with the transport sector responsible for around 20% of emissions.  
 
Europe has largely been the primary adopter of higher quality fuel standards with other OECD nations using European standards as international benchmarks. In 2014 the European Union developed the Euro VI standards, which are to date the highest level of fuel and vehicle emissions regulation. The implementation of Euro V and VI standards in the OECD has seen transport-derived pollution drop dramatically despite transport volumes increasing.  
 
The United States’ Environmental Protection Agency has adopted similar standards to the EU. The EPA has assessed that despite transport vehicle miles increasing by 108% between 1980 and 2022, aggregate US emissions of the six most common pollutants – including sulphur dioxide, carbon monoxide, and PM 2.5 – have decreased by 75%. PM2.5 alone decreased by 42% between 2000 and 2022.  
 
In 2023, after 30 years of regulatory updates, the theory of change behind Euro VI standards has succeeded. By implementing regulations primarily in the largest developed-country markets fuel refiners and vehicle manufacturers have been incentivised to make broad-scale upgrades to their manufacturing processes. It also means that the research and development costs to meet vehicle and emissions standards are absorbed in developed country markets – creating around a 30% reduction in costs once the vehicles reach developing markets. Today over 85% of fuel globally meets Euro VI standards. This means lower-quality fuel is now harder to import than cleaner fuel. 

Many middle and low-income countries however still fall short of Euro VI standards in vehicle manufacturing – due to the lower capacity to regulate the transport sector, and the lag in the life cycle of vehicles on the road. While generational vehicle turnover can influence some improvement in vehicle standards, due to localised car assembly and manufacturing procedures, real gains can only be made when the appropriate regulatory environment is established.  
 
CCAC partner the International Council on Clean Transport (ICCT) has been a lead actor in helping middle and low-income countries develop their planning frameworks for upgrading fuel and vehicle standards. The ICCT has been recently engaged in developing standards roadmaps in contexts as diverse as South Africa and ASEAN and has collected extensive experience on the considerations and consultations necessary for moving toward zero-emissions transport.  
 
“Depending on a country or region’s infrastructure and transport sector context, different approaches are necessary. In a region like ASEAN, all countries have different levels of development and fuel quality, and vehicle markets. Some are fuel importers, and some produce their own fuel, these factors all impact where they are at in terms of emissions reductions,” said Francisco Posada, Senior Researcher with the ICCT. 
 
With some of the worst air quality challenges in the world, ASEAN is a priority region for the ICCT efforts to improve emissions standards. This is due to trends in population growth, industrialisation and other economic activity combined with lagging emissions standards. This means it also has a high potential for improvement. Working on to establish a standards roadmap regional level enables stakeholders to push some of the lagging countries on a national level to meet their regional obligations. 
 
The differing pace of emissions standards change in some countries also means that countries which currently lag at Euro II or III levels may consider a more direct jump to zero-emissions infrastructure as more efficient than trying to catch up with changes to existing fossil fuel refinery infrastructure. 
 
“As we reach the limits of clean fuel with Euro VI and Euro VII standards, the next stage will be to start planning for the transition to zero-emissions transport, particularly in priority sectors such as trucking and public transport. That is a major decision, as technology like hydrogen fuel cells and electric battery systems require very different infrastructure needs, and the best choice differs based on the nature of the market in each country,” said Posada. 
 
The CCAC is currently helping individual ASEAN members such as Cambodia to develop its roadmap towards Euro VI standards. As a fuel importer, Cambodia already imports mostly EURO V quality fuel, and now seeks to formalise its monitoring and regulatory capacity for vehicle standards, while coordinating fuel and vehicle importers towards Euro VI standards beyond 2027.