Performance and emissions of a diesel engine using sunflower biodiesel with a renewable antioxidant additive from bio-oil

•Biodiesel oxidation stability can be improved with a bio-oil derived additive.•Performance and emissions of a diesel engine are not significantly modified by this additive.•Biodiesel, with and without additive, improves most of the emissions measured. The aim of this study is to test the behaviour of sunflower biodiesel in a diesel engine after being treated with a natural antioxidant additive produced from bio-oil extraction (final dosage of bio-oil compounds in doped biodiesel of 1.9 wt%). The influence of this renewable additive in both the engine performance and the produced emissions was evaluated. Five more fuels were used for the sake of comparison: petroleum diesel, neat sunflower biodiesel without additives, commercial biodiesel, commercial B10 blend and another B10 blend prepared from petro-diesel and doped sunflower biodiesel. Brake power was found to be similar for the six fuels, while the brake specific fuel consumption and the brake thermal efficiency were higher for biodiesel fuels. Only slight differences (