i use 5w20 in my engines that require it i just changed the oil in one of my 4.6 fords and used 5w20 and a motorcraft filter and will change it in 5000 miles engine has 154,000 miles on it and runs like new i bought it with 11,550 on it and only used 5w20 its entire life..
5w30 wont hurt that engine but 5w20 is ideal.. All the seminars we attend some dyno equipped all show 5w20 to be great