white smoke out of exhaust when when first starting then runs fine 60000 miles

I know a guy who went through bout the same thing.he would start it up someone saw it do this..a little white smoke came out of the tail pipe of his Truck,2000 or 2001 F150 4.6L engine..he was a Regional Commercial Manager at a Large Retail Parts Store.over a few States and he put a lot of miles on it.i know it calls for 5W20 oil cause i have the same truck. anyways,this guy told him to run 20W50 full synthetic oil in it..he started doing this,and guess what,NO more white smoke at any time! he still has the truck and still driving it,going on 500,000 miles!!! I know that this is thick oil,but,hey it's working and a very quiet engine, original factory engine! don't know which engine you have,cause you didn't list it in your question,(could be any one of the four engines that your truck calls for that year) it's up to you,it's your truck...good luck...