MANUFACTURER Rolls-Royce has received a major boost after gaining US approval to market one of its latest generation marine gas engines.The company said the United States Environmental Protection Agency (EPA) had approved for sale in the US a state-of-the art marine gas engine designed to improve fuel efficiency, dramatically cut harmful methane emissions and meet strict international environmental standards set to take effect in 2016.  Neil Gilliver, President - Merchant, Rolls-Royce said: "This Certificate of Conformity by t......for the full story register now for free or login below...