What is the effect of variations in gas composition and engine performance?
With regard to the different gas compositions that you have available, the issues will depend on what the percentage differences are for the various gases that make up the mix and also on what your local regulations are with regard to emissions. If the gas compositions do not differ very much – say the differences on methane content are in the range below 5%, then it is probable that you will be able to tune for somewhere in between the optimum for each and there will not be significant differences in engine performance. However, there could be differences in emissions levels. In some situations this may not be a concern. In the case of countries that have stringent emisssions regulations, it would be difficult to meet the regulations. So it really depends very much on how large the variations in gas are and what your emissions regulations allow.
