Results of numerical analysis of methane and gasoline combustion in multipoint ignition SI engine are presented in the paper. Work parameters of engine fuelled with methane lean mixtures of λ = 1.45 and 1.8 for three configurations of spark plugs (one, two and four active spark plugs) are compared. These configurations were chosen taking into consideration earlier research concerning numerical modelling and experiments. The results of carried out analysis proved that using two spark plugs at air excess number λ = 1.8 caused that engine work parameters are similar to case of mixtures of λ = 1.45 with one spark plug configuration. Simultaneously, the emission of nitric oxide was decreased more than eight times and the concentration of carbon dioxide in exhaust gases was 20% lower.