Nanotechnology is usefull in developing lighter and stronger materials which will be useful for creating vehicles that are both faster and safer. Combustion engines will also benefit from parts that are more hard-wearing and more heat-resistant. A plastic nanocomposite is being used as a scratch-resistant, light-weight, and rust-proof, and generates improvements in strength and reductions in weight, which lead to fuel savings and increased longevity. Metal nanocrystals might be incorporated into car bumpers, making the parts stronger, or into aluminum, making it more wear resistant. Metal nanocrystals might be used to produce bearings that last longer than their conventional counterparts. Aqueous polymer dispersion products contain polymer particles ranging from ten to several hundred nanometers in size and these are used in exterior paints, coatings and adhesives.