Bardahl 4019 Engine Tune Up - 12 fl. oz. Proprietary chemical formula dissolves harmful gum and varnish and removes sludge Increases engine performance by cleaning rings, pistons, valves, and other close tolerance parts Chemically 'tunes-up' the engine by loosening sticky valves, lifters, and rings Dispersants and detergents keep removed deposits in suspension until the motor oil is drained Improves engine efficiency and performance, extending the life of the vehicle