The present experimental investigation attempts to explore the performance characteristics of an existing single-cylinder four-stroke compression-ignition engine operated in dual-fuel mode with hydrogen as an alternative fuel. Experimental investigation was conceded with the engine being subjected to different loads at a predefined flow rate of hydrogen induction. A Timed Manifold Injection (TMI) system has been developed to vary the injection timing and the durations. The optimized timing for the injection of hydrogen was 10 degrees CA after top dead center (ATDC). From the study it was observed that hydrogen with diesel results in increased brake thermal efficiency (BTHE) by 15.7% at 40% full load, volumetric efficiency (Vol. Eff.) by 78.5% at full load condition compared to baseline diesel operation. Hydrogen enrichment registered a maximum reduction of 41.4% in specific fuel consumption (SFC) of diesel at 20% full load. A pareto-optimal front was then obtained using nondominated sorting genetic algorithm (NSGA). Analysis of the front was done to identify the separate regions for Brake specific energy consumption (BSEC), Brake thermal efficiency (BTHE) and Volumetric efficiency (Vol. Eff.). Designed experiments were then conducted in these focused regions to verify the optimization results and to identify the region- specific characteristics of the process. Copyright 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.