Abstract: An additive concentrate for use in fuels, especially in gasoline for internal combustion engines, comprising (a) 0.2 to 10 wt. % ashless friction modifier which is liquid at room temperature and pressure selected from (i) n-butylamine oleate or derivatives thereof, (ii) a substance comprising tall oil fatty acid or derivatives thereof, and (iii) mixtures of (i) and (ii); (b) 10 to 80 wt. % deposit inhibitor, and (c) carrier fluid. The particular selection of friction modifier (a) enables a stable additive concentrate to be formulated without the need for additional solubilising agent for the friction modifier, while containing sufficient friction modifier to achieve a significant benefit in fri loss, when incorporated in gasoline used to fuel an internal combustion engine, and hence an improvement in fuel economy.