5W or 5-W may refer to: Units of measurement 5°W, or 5th meridian west, a line of longitude 5 watts 5 weeks 5 wins, abbreviated in a Win–loss record (pitching) Science, technology and transportation 5w, a viscosity grade of motor oil I-5W, westbound Interstate 5 Interstate 5 in California AD-5W, a version of the Douglas A-1 Skyraider 5W, IATA airline code for Astraeus Airlines Other uses Five Ws: Who?, What?, When?, Where?, and Why? "Which Was What Was Wanted", an alternative to Q.E.D. 5W Public Relations, a public relations agency 5W, production code for the 1982 Doctor Who serial Four to Doomsday See also W5 (disambiguation)