A technique is provided for improved response of internal combustion engines to increased load demands. The engine is equipped with an air storage tank that stores compressed air. The air may be stored at an elevated pressure (e.g., manifold air pressure) during normal full load operation of the engine. Valving maintains the compressed air isolated during normal operation. During transitory periods of higher power output demand, the compressed air is directed to the engine, and output of a turbo-driven compressor can be vented to avoid surge. The technique allows for quicker reaction to load demands, and improved combustion during transitory periods, and reduced particulate and smoke emissions.