The projected economic and environmental impacts of global warming means that many industries are being pressured by society and government regulations to reduce their greenhouse gas (GHG) emissions. Also, consumers expect that the quality and performance of the products that they use will not decrease, and that companies will employ more sustainable production techniques and renewable resources when making them. A key strategy to reduce GHG emissions in the transport industry is to improve the fuel efficiency of vehicles by reducing their weight. Polyphtalamide (PPA), a high-performance engineering plastic used as an alternative to metal components, is usually filled with talc. High-temperature biocarbon, a possible alternative to talc, was blend mixed in 20 and 30% with PPA and compared to similar talc-filled manufactured composites. We found that biocarbon-filled composites can match the mechanical and thermal properties of the talc composites, at a lower density, opening the possibility of increasing fuel efficiency. Acknowledgements: This research was financially supported by: i) Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph – Bioeconomy for Industrial Uses Research Program (Project # 030332); ii) Natural Sciences and Engineering Research Council (NSERC), Canada Discovery Grants Project # 400320 and 401111; iii) the Ontario Research Fund, Research Excellence Program; Round-7 (ORF-RE07) from the Ontario Ministry of Research, Innovation and Science (MRIS) (Project # 052644 and 052665).