In early 2020, UK-based independent testing firm Emissions Analytics published a study claiming that tire particulate wear emissions were 1,000 times worse than exhaust emissions ( earlier post ). Since that study, which was transparently designed to quantify the worst-case tire emissions under legal driving, Emissions Analytics has been testing and analyzing tire wear emissions in more detail across a wider range of driving conditions, and has performed a detailed chemical analysis of hundreds of new tires. The company has also worked with the National Physical Laboratory in the UK objectively to quantify the uncertainties in the measurements of chemical composition. Emissions Analytics now concludes that, comparing real-world tailpipe particulate mass emissions to tire wear emissions, both in ‘normal’ driving, the latter is actually around 1,850 times greater than the former. Quoting such ratios, however, needs careful interpretation. The fundamental trends that drive this ratio are: tailpipe particulate emissions […]