I don't know if it is because of studies and statistical info but I noticed that the int rates and terms of those loans always does things by intervals of 20. So when you went from the mid score of 720 to 716 you "switched" categories. From what I have seen FICO scores can change anytime based on creditor updates, aging, history, etc. Even after that it is still when the bureau updates. I had one creditor tell me they update monthly after my statement cuts. I noticed it showed up approx a week later on the credit report and I got a alert from myfico because I had a balance increase of more than $5. I think it can be hit or miss. Some creditors for whatever reason update quarterly. Hope this helps. Also, if you have scorewatch it can be set to when you reach a better interest rate, pretty cool.