Abstract: An optimized engine charge air-cooling system for an internal combustion engine includes a charge air cooler side mounted along an outboard side of each engine cylinder bank of the engine. The charge air coolers extend the full length of the cylinder banks. The charge air coolers each include a housing, a core, an air inlet and an air outlet. The charge air cooler inlets are connected to an outlet of a compressed air source, such as a turbocharger, through cooler intake headers. The charge air cooler outlets are connected through cooler outlet headers to cylinder intake ports of cylinders in the cylinder banks. The design of the charge air-cooling system allows for highly effective cooling of charge air with a corresponding small drop in charge air pressure. These features combine to achieve the result of decreased engine nitrogen oxides (NOx) production and increased engine fuel economy.