Division 2.5.2.1 F1

For a dual-fuel engine family where the engines are calibrated for a specific LNG gas composition resulting in a λ-shift factor not differing by more than 3 % from the λ-shift factor of the G ₂₀ fuel specified in Annex IX, and the ethane content of which does not exceed 1,5 %, the parent engine shall only be tested on the G ₂₀ reference gas fuel, or on the equivalent fuel created using an admixture of pipeline gas with other gases, as specified in Appendix 1 of Annex IX.