An internal combustion engine enhancement system for increasing vehicle fuel mileage over a duration of a plurality of tanks of fuel used in a vehicle. The internal combustion engine enhancement system generally includes a fuel additive which includes a volume of carrier fluid and a plurality of fine particles within the carrier fluid. The carrier fluid with the fine particles is added to the fuel in the fuel tank of a vehicle. The fine particles are reduced in size to nanoparticles by dissolving and abrading to less than 1,000 nanometers where after they are transferred to the engine during normal operation of the engine. The nanoparticles lubricate the engine components and fill in voids within the sleeve to increase engine lubricity. Alternatively, larger particles (e.g. 0.25 inches in size) may be added to the fuel where fine particles and nanoparticles are created via abrading and dissolving.