This report describes work performed jointly by Mahindra & Mahindra and IIT Delhi, including both simulations and single-cylinder engine development for three wheeler application, to quantify the effects of various parameters on the performance and NOx emission of an internal combustion engine fuelled by hydrogen. AVL Boost software was used to simulate the experimental conditions, by using Vibe 2-Zone combustion and Woschni heat models, together with kinetic equations for emission calculations. Developed AVL Boost Model was validated against the test result from a modified single cylinder CNG engine for three wheeler application fuelled with Hydrogen by comparing the performance and NOx emission at the same operating conditions. A good agreement was obtained between the results of the Boost Model and Experimental results.With Validated Model, a detailed parametric study was done by simulating full throttle and part throttle engine performance to calculate power, BMEP, BSFC, exhaust temperature and NOx emission to understand the effect of compression ratio, A/F ratio, and ignition timings on same. Consequently with this data, Design of experiment (DOE) technique was used to find the effect of individual parameter and to obtain the optimum combination. With Optimized parametric data, engine was fine tuned and the result has shown in improvement in power and BSFC by 11.16% and 18% respectively. Also overall reduction in NOx and exhaust temperature is observed.Results from the investigations reveal the potential of hydrogen as a fuel for IC engine application to reduce the dependency on conventional fuel and the carbon emission.