E40 may refer to: Nimzo-Indian Defense, Encyclopaedia of Chess Openings code European route E40, a road extending from France to Kazakhstan E-40 (born 1967), American rapper GE E40, a locomotive E40, the name for the fuel blend of 40% ethanol and 60% gasoline E40 screw, a type of Edison screw HMS E40, a 1916 British E class submarine