Whether you’re driving a personal car or a commercial vehicle, exhaust emissions from petrol and diesel engines significantly impact air quality and contribute to atmospheric pollution. To address this, the European Union introduced the Euro standards, a series of legislative measures aimed at limiting harmful vehicle emissions.
Since their introduction in 1992, six sets of regulations have been implemented. Despite the UK no longer being a part of the EU, the Euro emissions standards continue to play an important role in ensuring sustainability and supporting trade. In this guide, we’ll explore these standards in detail and discuss their implications for fleet management.
The Euro emissions standards are a set of environmental regulations established by the European Union (EU) to reduce harmful emissions produced by new vehicles with internal combustion engines.
These standards differ based on the type of vehicle, with specific limits applied to passenger cars, lorries, and coaches. Their primary goal is to minimise the environmental impact of exhaust pollutants such as carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC), and particulate matter (PM).
To keep pace with technological advancements and growing environmental needs, new Euro standards are introduced approximately every four to five years for increased control over vehicle emissions.
Introduced in 1992, the Euro 1 standard marked a significant step in regulating emissions from light goods vehicles. It established specific limits for CO emissions at 2.72 g/km and for a combination of HC+NOx at 0.97 g/km for both petrol and diesel vehicles. Additionally, it introduced a PM limit of 0.14 g/km for diesel vehicles.
To meet these requirements, manufacturers were mandated to equip new vehicles with catalytic converters and transition to using unleaded petrol.
The Euro 2 standard, introduced in 1997, was built on the foundations of Euro 1. For petrol vehicles, the regulation set new thresholds for CO at 2.2 g/km and for a combination of HC+NOx at 0.5 g/km.
For diesel vehicles, the Euro 2 standard imposed even tighter restrictions compared to Euro 1. The limits for diesel engines were set at 1.0 g/km for CO, 0.7 g/km for HC+NOx, and 0.08 g/km for PM.
The Euro 3 standard came into effect in 2001. A key change was the introduction of a separate NOx limit for diesel engines, as well as individual limits for HC and NOx emissions in petrol engines.
For petrol vehicles, the Euro 3 limits were set at 2.3 g/km for CO, 0.20 g/km for HC, and 0.15 g/km for NOx. Diesel vehicles faced limits of 0.64 g/km for CO, 0.56 g/km for a combination of HC+NOx, 0.50 g/km for NOx alone, and 0.05 g/km for PM.
The introduction of Euro 3 also revised the testing process by eliminating the engine warm-up phase to make sure emissions were measured under more realistic conditions.
The Euro 4 standard was introduced in 2006. For petrol vehicles, the emission limits were set at 1.0 g/km for CO, 0.10 g/km for HC, and 0.08 g/km for NOx. Diesel vehicles were met with tougher restrictions of 0.50 g/km for CO, 0.30 g/km for a combination of HC and NOx, 0.25 g/km for NOx alone, and 0.025 g/km for PM.
While Euro 4 placed no particulate emission requirements on petrol vehicles, it did encourage advancements in diesel technology. For instance, some Euro 4 diesel cars were equipped with particulate filters.
The Euro 5 standard was introduced in 2009 and officially came into force in 2011. Notably, it marked the first time a PM limit was applied to petrol engines, specifically those with direct injection technology.
For petrol vehicles, the emission limits were set at 1.0 g/km for CO, 0.10 g/km for HC, 0.06 g/km for NOx, and 0.005 g/km for PM. Diesel vehicles faced stricter demands, with limits of 0.50 g/km for CO, 0.23 g/km for HC+NOx, 0.18 g/km for NOx alone, and 0.005 g/km for PM, along with a particulate number limit of 6.0 × 10^11 particles per km.
These new restrictions applied to type approvals for vehicles from September 2011 and became mandatory for diesel vehicles from January 2013. As a result, particulate filters became a standard feature in all new diesel cars.
Euro 6, the current emissions standard, was first introduced in 2014 and has undergone further revisions in 2018, 2019, 2021, and 2022. For petrol vehicles, the Euro 6 limits are set at 1.0 g/km for CO, 0.10 g/km for HC, and 0.06 g/km for NOx. Direct injection petrol engines are also subject to a PM limit of 0.005 g/km and a particulate number limit of 6.0 × 10^11 particles per km.
Diesel vehicles have stricter requirements, with limits of 0.50 g/km for CO, 0.17 g/km for a combination of HC and NOx, 0.08 g/km for NOx alone, and 0.005 g/km for PM. A particulate number limit of 6.0 × 10^11 particles per km also applies to diesel engines.
Set to come into effect on 1 July 2025, the Euro 7 emission standard will introduce a new set of regulations designed to address the latest environmental challenges, including those posed by electric vehicles (EVs).
One of the distinct aspects of Euro 7 is its focus on non-exhaust emissions, aiming to reduce pollution from sources such as brake dust and tyre wear. Moreover, vehicles will be tested under a wider range of conditions to guarantee that they meet the standards throughout their lifecycle. For EVs, the Euro 7 standard will include rigorous tests on battery health and performance.
While the Euro 7 standard maintains the same exhaust emission limits for cars and vans as Euro 6, it will introduce stricter controls on solid particle emissions. For heavy goods vehicles, Euro 7 will also impose more stringent limits on pollutants, including nitrous oxide (N2O).
Although the EU's emissions standards primarily relate to vehicle manufacturers, fleet managers must also stay informed about these regulations as they plan for future integrations.
At MICHELIN Connected Fleet, our solutions enable fleet managers to track the emissions of each vehicle in their fleet, helping to lower fuel consumption in order to ensure compliance with set standards. And, with driving behaviour tools, you can gain valuable insights into each driver's habits and encourage fuel-efficient driving practices.
Likewise, our consultative service provides all the information you need to electrify your fleet, supporting your efforts in the transition towards Net Zero. If you’re interested, then be sure to make an enquiry into our services today.