Dunno if it's okay or not, but after I had a stuck fuel injector back in late October, I started using Amsoil HP Marine TC-W3 in my Explorer. For every 4-4.5 gal of fuel, I add 1 oz of oil, which is a 512-576:1 fuel to oil ratio. I use the enhanced trip meter to determine the amount of fuel used since last fill up and add oil to target 512:1. When I top off the tank, it will usually take a tad more fuel than what was indicated in the enhanced trip meter (making it slightly more diluted than the 512:1 ratio).
Been running like this for about 4300 mi, but can't really claim any increase in fuel mileage or idle improvements. No kablooey as of yet...