Just rang the Mitsubishi 1300 13 12 11 number & asked how LPG affects OEM warranty on new Diesel Triton's. The nice Girl said that it is not approved and should a problem happen (resulting from LPG &/or it's installation) then you can expect it not to be covered under warranty. She also said that it should be in the "Service and Warranty Manual" that owners have.
She could not provide anything in writing confirmation. She also mentioned that the new V6 diesel is expected to be available for the Pajero in the 4th quarter this year...