Soot-free transport

Diesel engines are responsible for significant health and climate impacts in the transportation sector. A leapfrog to soot-free engines equivalent to Euro 6/VI or US 2010, coupled with fuels containing no greater than 10 parts per million sulfur, would require diesel engines to use a diesel particulate filter that effectively eliminates the fine particle and black carbon emissions responsible for the vast majority of these impacts. This page defines the key areas of knowledge needed to understand these impacts and address them, including key resources from the ICCT and other international expert groups.

Impacts of diesel engines

Some great resources to understand the heath impacts of outdoor air pollution, the contributions from the transport sector to outdoor air pollution, and the contributions of diesel exhaust to health and climate impacts in the sector include the following:

Impacts of black carbon

The largest component of diesel particulate matter from pre-Euro VI and pre-US 2007 engines' is black carbon, a short-lived climate pollutant that contributes substantial near-term climate warming. Resources that capture the impacts of black carbon and their emissions from diesel vehicles include the following:

Soot-free engine and after-treatment technologies and fuels

Soot-Free engines require diesel fuels containing 10 parts per million sulfur, or a switch to alternative gas or electric drive engines. For an understanding of diesel fuel requirements, see the following resources:

A soot-free diesel engine delivers a 95% reduction in fine particulate matter emissions, and up to a 99% reduction in black carbon or particulate number emissions through the use of a diesel particulate filter. The following resources help explain the technology pathway and cost of these filters as part of a package of technologies needed to bring soot-free emissions in the transport sector:

Examples of best practices for new and in-use engines

The best practices for requiring soot-free engines in new vehicles are the adoption and implementation of Euro V diesel fuels alongside the implementation of emission standards such as the US Tier 3, China 6, or Euro 6 emission standard for light-duty vehicles, and the Euro VI or US 2010 emission standard for heavy-duty vehicles.

Compliance and enforcement tools and mechanisms

Experience varies widely among countries in their ability to monitor and enforce compliance with vehicle emission standards.

Remote sensing is an emerging strategy to independently monitor and assess the real-world performance of vehicles to identify high emitters for follow-up and to identify systematic cheating among vehicle manufacturers.