The road to zero-emission vehicles: CO2 emissions standards from 2025 and beyond

The road to zero-emission vehicles: CO2 emissions standards from 2025 and beyond
26 May 2021

In December 2019, EU leaders endorsed the objective of making the EU climate-neutral by 2050. The Paris Agreement requires the entire transport sector to accelerate towards zero emissions. Transport accounts for around a quarter of GHG (Greenhouse Gas) emissions in the EU currently. Passenger cars and vans (light commercial vehicles) are responsible for around 12% and 2.5%, respectively, of total EU emissions of carbon dioxide (CO2), the main greenhouse gas. 

CO2 Emissions 

Greenhouse Gas Emissions are the source of global warming; a large part of these are CO2 (carbon dioxide) emissions, but Greenhouse Gas Emissions include other gases, such as methane (CH4) and nitrous oxide (N2O). The European Green Deal, presented in December 2019, reinforces the focus on the transport sector to reduce CO2 emissions. The Green Deal is the roadmap for making the EU’s economy sustainable and it is seeking a reduction of 90% in Greenhouse Gas emissions in the transport sector by 2050 to achieve climate neutrality. Sustainable mobility is one of the policy areas of the European Green Deal.

The Paris Agreement sets out an action plan to hold the increase in global average temperature well below 2°C above pre-industrial levels and to pursue efforts to keep it to less than 1.5°C above pre-industrial levels. 

In September 2020, as part of the European Green Deal, the European Commission proposed to raise the 2030 Greenhouse Gas emissions target to at least 55% reduction compared to 1990. This 2030 climate target sets the EU on the path to becoming climate neutral by 2050. The detailed plan to achieve this target looks at emissions reduction in different areas, including road transport.

Reducing climate impacts

Scientists say that the environmental impacts associated with a temperature increase of 1.5°C will have less devastating effects than higher levels of global warming. Additional warming, beyond a 1.5°C temperature increase, will result in increasingly severe impacts. Scientists advise that Greenhouse Gas Emissions need to drop rapidly to get on track to limit the global temperature rise to 1.5°C. In this context, the UK government wants almost every car and van to have zero emissions; it expects to see as many as 70% of new car sales and up to 40% of new van sales to be low emission by 2030. In April 2021, the UK government set a target reduction of Greenhouse Gas Emissions of 78% by 2035, compared to 1990 levels.

Consumer demand and regulatory pressures are encouraging manufacturers and suppliers to provide solutions to the CO2 reduction challenge. The industry’s response will depend on the nature of the detailed legislation itself, and automakers will continue to make technological improvements. There is a need for those in the transport industry to monitor the emissions standards continuously and to understand how the legislation is changing. 

Emissions data and targets post-2025

Data on CO2 emissions of all new passenger cars and light commercial vehicles are being recorded and collected by the European Commission. This process allows monitoring of the overall emissions and assessment of compliance with the targets for manufacturers. CO2 emissions average targets of 95 g/km for passenger cars and 147 g/km for light commercial vehicles were in place for the year 2020. A regulation on post-2025 targets for passenger cars and LCVs was finalised in 2019. 

Regulation 2019/631, published in April 2019, sets post-2025 CO2 emissions targets for passenger cars and LCVs. Since then, amendments and complementary regulations have been published, including a recent one on additional monitoring requirements for light-duty vehicles. 

The regulation sets the EU fleet-wide CO2 emissions targets from 1 January 2025, for both passenger cars and LCVs as follows:

  • From 1 January 2025, an EU fleet-wide target for the new passenger cars fleet corresponding to a 15% reduction of the EU fleet-wide target in 2021
  • From 1 January 2025, an EU fleet-wide target for the new light commercial vehicles fleet corresponding to a 15% reduction of the EU fleet-wide target in 2021
  • From 1 January 2030, an EU fleet-wide target for the new passenger cars fleet corresponding to a 37.5% reduction of the EU fleet-wide target in 2021
  • From 1 January 2030, an EU fleet-wide target for the new light commercial vehicles fleet corresponding to a 31% reduction of the EU fleet-wide target in 2021.

CO2 emissions targets for manufacturers will be defined starting from these required reductions in the emissions of the EU-wide fleet, based on the average mass of new vehicles in the market for the manufacturer. A proportion of new vehicles on the market for each manufacturer will be expected to be zero and low-emission vehicles. If the percentage of vehicles with zero and low emissions exceeds the benchmarks, the targets for the manufacturer will be relaxed. The following criteria have been defined:

  • From 1 January 2025, a zero-emission and low-emission vehicles benchmark equal to a 15% share of each of the new passenger cars and new light commercial vehicles fleets will apply.
  • From 1 January 2030, the following zero-emission and low-emission vehicles benchmarks will apply:
    • A benchmark of 35% share of the fleet of new passenger cars.
    • A benchmark of 30% share of the fleet of new light commercial vehicles.

The post-2025 CO2 emissions targets for passenger cars and light commercial vehicles are due to be reviewed within the context of the 2030 Climate Target Plan. The European Commission published an impact assessment on the revision of these standards in October 2020, and a proposed regulation is expected by the end of 2021.

Following the UK’s exit from the EU and the end of the implementation period, in which EU law still applied, at the end of December 2020, the UK now implements and enforces emissions legislation independently from the EU. The UK has issued CO2 emissions targets for passenger cars and light commercial vehicles for the next few years and post-2025. UK targets are in line with those of the EU, with some specific provisions that adapt the EU regulations to the UK market. The UK targets are contained in a dedicated page in Ricardo’s Emissions Legislation Database EMLEG.

PaREGEn – Particle Reduced, Efficient Gasoline Engine

The PaREGEn (Particle Reduced, Efficient Gasoline Engines) project was executed under the Horizon 2020 framework programme. The project was co-ordinated by Ricardo and ran from October 2016 for 39 months. A consortium of 17 partners took part, including OEMs, research institutions, Tier 1 suppliers and engineering service providers.

In an era of rapidly increasing vehicle electrification, the gasoline engine remains a vital part of the passenger car powertrain portfolio. This project covered further development of gasoline engines used in mid to premium-sized cars. The aim of the project was to develop a new generation of engine technologies that were significantly more fuel-efficient than the best 2015 equivalent vehicles, to demonstrate pollutant emissions levels compliant with the Euro 6 RDE (Real Driving Emissions) limits and particle number emissions measured down to a 10 nm size threshold.


Using state-of-the-art development techniques, the optimal trade-offs between cleanliness and efficiency were identified. The project used data from optically accessed single-cylinder engines, a range of modelling and simulation tools and applied novel components for the development of the next generation of gasoline engines.

The overall concept and technical approach of the project comprised of three major elements:
1.    Research for improved understanding.
2.    Innovation and demonstration of new technology combinations where the developed know-how, software and control strategies were implemented in two novel, optimised gasoline engine vehicles.
3.    Independent assessment of the vehicles’ performance in respect to the project’s targets.

Figure 1 Overview of the PaREGEn project

Ricardo and the PaREGEn Project - demonstrating 15% CO2 emissions reduction

Ricardo co-ordinated the PaREGEn consortium and also played a vital role in the development of a lean-burn demonstrator vehicle.

Lean-burn combustion is a formidable means for reducing the CO2 emissions of gasoline engines, but demands sophisticated emissions control.

The lean-burn operation has been known to improve fuel economy since the earliest internal combustion engines were developed. Lean operation can reduce both the heat losses and the pumping work.
In order to meet the combined climate and air quality challenges described above with lean gasoline engines, a new generation of technology solution was required. The focus returned to lean-homogeneous combustion systems, which produce the lowest engine-out NOX emissions. Advanced fuel injection, ignition, valvetrain and boosting technologies were employed to increase the air-fuel ratio possible, with stable combustion.

The range of technologies used offers a sound basis for the future development and viability of the ICE (internal combustion engine) in a heavily electrified powertrain for such vehicles.

The result of this exciting piece of work was an engine that delivered brake specific fuel consumption benefits exceeding 10% and a peak brake thermal efficiency of 42%. Both of these have a direct impact on reducing CO2 emissions significantly. A combination of testing and simulation demonstrated how the target of 15% CO2 reduction would be achieved. The demonstrator vehicle also achieved a NOX conformity factor (CF) below 1.0, in independent RDE tests. The conformity factor is the discrepancy that the Euro 6 standards allow between emissions on the road and emissions obtained during lab-based testing. The current maximum CF value allowed for all newly approved vehicles in the EU for NOX emissions is 1.43 (Euro 6d and following stages). To understand more about the real driving performance of the PaREGEn demonstrator vehicle, please visit Ricardo’s dedicated web page.

Figure 2 Demonstrator vehicle under bonnet layout

Learn more about PaREGEn and EMLEG

To find out more about the consortium work as a whole, visit PaREGEn or contact Andy Lane, Principal Engineer at Ricardo; you can talk to Andy for a demonstration of the vehicle as well. 

Within EMLEG, you can discover the official CO2 emissions standards and exhaust emissions standards for all the main markets, EU, US, California, China, India, Brazil and Japan, as well as for many other countries worldwide. EMLEG includes all the details of the Euro 6 standards and some initial information on post-Euro 6 standards. New information is added to EMLEG as new standards are released; so that you can keep track of all the amendments and new proposed regulations. EMLEG contains further details of the regulation and calculations of EU CO2 emissions targets for passenger cars and light commercial vehicles. 

EMLEG is an online database that provides a way to quickly track and interpret emissions standards by country and market sector. Discover more about EMLEG and request a demo