Fig. 5: Tailpipe emissions from the combustion of diesel and HyFiT fuels.
a–c, Tailpipe emissions of diesel, HyFiT-20% and HyFiT-40%: CO2 (a), NOx (b) and PM (c). Results are shown for additized HyFiT fuels and three engine calibration cases: measured emissions from vehicle tests with the manufacturer’s engine calibration, denoted as ‘drop-in’ (white circles); and estimated emissions of HyFiT fuels with an engine calibration that targets either the same tailpipe NOx emissions as diesel (grey circles) or the same engine-out PM emissions as diesel (black circles). Limits of the upcoming Euro 7 legislation are shown as grey horizontals (b and c). Dotted curves are guides to the eye. Numerical values of emissions are presented in Supplementary Table 9. An alternative figure showing PM over NOx tailpipe emissions is presented in Supplementary Fig. 15.
