Been using 5w20 castrol edge FST in my 2010 fusion 3.0 v6 since new. Been noticing that with edge fst it burns a lil oil around 5000 miles. I use prolly 5 or 6 full tanks of E85 every OCI. Not sure if the E85 causes it or it's esdge fst. Anyone find this with edge FST in their vehicles?