Time for a boost: Three ways to better leverage the European Union’s CO2 regulation for heavy-duty vehicles


To address the ever-growing CO2 emissions from road freight and passenger transport, and to meet the objectives of the Climate Law, the European Union (EU) adopted CO2 standards for heavy-duty vehicles (HDVs). The regulation mandates fleet-wide emission reductions of 15% in 2025 and 30% in 2030 for new vehicles, compared to a 2020 baseline.

In June 2021, the EU published official CO2 certification data for the first time for trucks. This might seem like an insignificant step in the overall regulatory framework, but this unprecedented dataset is a goldmine. In addition to including detailed information on the rate of technology adoption, it enables the tracking of progress made by EU truck manufacturers towards the climate goals set out by the European Commission. As it turns out, the heavy-duty CO2 legislation will require a significant boost to align the industry with these goals. Based on lessons learned from the 2019–2020 certification data, here are three ways to better leverage the EU’s existing heavy-duty CO2 legislation.

1. Increase the stringency of the CO2 standards to drive technology adoption. Although manufacturers have made ambitious pledges on zero-emission vehicle (ZEV) production, only a handful of pilot models were registered in 2020—three according to the official data, and up to 47 according to other datasets available to the ICCT. The certification data suggests that the improvements required to meet the 2025 target can largely be achieved by exploiting the low-hanging fruit technologies and with little-to-no deployment of zero-emission vehicles. Still, ZEVs are the only way to quickly and substantially decarbonize transport. Early ZEV adoption will be crucial to align the HDV sector with the EU’s climate ambitions, and driving this adoption will require stricter standards.

To quickly decarbonize, the industry is also looking into different technology pathways including alternative fuels. One fuel that does not seem viable, though, is natural gas, which has been described by my ICCT colleague as “a bridge to nowhere”. Despite the lower carbon content of the fuel, it is fed into less efficient engines than their diesel counterparts. Our analysis reveals that natural gas trucks can emit even more CO2 than the equivalent diesel trucks. Setting the appropriate stringency for the standards will ensure that only technologies that deliver real-world benefits are further exploited. To this end, on-board fuel and energy consumption monitoring (OBFCM), as well as market surveillance activities such as in-service testing, will be crucial in ensuring the effectiveness of the CO2 legislation.

Manufacturers are exploiting other ways to reduce CO2 emissions in conventionally powered trucks and buses. In 2020, the best-in-class cycle-average engine efficiency was 4% higher than for 2016 trucks. The 2020 best-in-class aerodynamic performance was an impressive 20% better than the 2016 value. At the manufacturer level, Scania has already achieved about 5% of the 15% reduction required to meet its 2025 target, with still five years to go. However, the industry average lags far behind the best-in-class values. Emissions vary a lot across manufacturers and models, highlighting an uneven rate of technology adoption across the industry. Pushing fleet-wide adoption of efficiency and zero-emission technologies will certainly require more stringent targets.

2. Widen the scope of the legislation to increase CO2 emission savings. The HDV CO2 standards currently cover only the four heaviest truck segments, which represent about 65% of newly registered HDVs in the EU. Our recent analysis shows that extending the regulation to all trucks and trailers would increase the current CO2 emission savings by up to 50%, as shown in the figure below.

Extending the scope of the standards starts with an accurate and comprehensive CO2 and energy consumption certification procedure. Several of the truck segments that are not subject to emission reduction targets are already covered by the certification regulation and could be included in the standards with little additional effort. In addition, the upcoming amendment to the certification procedure should widen its scope to include light and medium trucks, buses, and coaches, as well as the contribution of trailers to the combined vehicle’s emissions. We estimate that adopting specific performance standards for trailers and semi-trailers alone would increase the benefits of the current regulation by a staggering 24%. As the CO2 standards are reviewed in 2022, the European Commission has an opportunity to also apply emission reduction targets to these other HDV segments. Setting an appropriate standard for buses will be crucial.

Figure. Cumulative CO2 savings from extending the HDV CO2 standards to additional vehicle segments compared to the currently adopted regulation, for the period 2020–2035. The green data labels show the increase in CO2 savings relative to the Adopted CO2 standards case.

Our analysis of the certification data showed an overall greater adoption of advanced technologies in segments that are subject to reduction targets. Extending the scope of the regulation could drive the adoption of such technology in all HDV segments, and incentivize a more rapid transition to zero-emission HDVs in the easy-to-electrify segments, such as urban trucks and buses.

3. Better capture real-world use cases in the certification procedure. Trucks and buses come in many different shapes and forms. Analysis of the certification data reflects just how challenging it is to capture the wide range of vehicle applications that are dubbed “heavy-duty vehicles.” The European legislation segments the market according to the vehicles’ technical characteristics—i.e., weight, length, axle configuration, cabin type, etc.—but it does little to account for different use cases. As a result, use cases that present significantly different potentials for CO2 emissions reduction are grouped together. To address this issue, the European Commission defined all trucks that are not intended for the delivery of goods as “vocational” and excluded them from the CO2 emissions reduction requirements. Unfortunately, our analysis shows that this reduces the stringency of the targets by up to 2% for some manufacturers.

Better capturing the spectrum of heavy-duty vehicle use cases in the certification procedure will enable the introduction of targets that are more representative of different use cases’ emission reduction potentials. It will also help address the gap between certified and real-world emissions, and assess the charging and refueling infrastructure needs as the industry transitions to zero-emission vehicles.

The EU has furnished a lot of work to establish a solid ground for CO2 legislation for trucks and buses over the past years. It is now time to ramp up the ambition and make better use of the available regulatory tools to ensure that the decarbonization of road transport is aligned with the EU’s climate goals.