I know on the older new edge cars a lot of people used the 315s. And I have seen a few people use 305s on these cars but I cant seem to find anyone who has used 315s. They arent that much wider than the 305s.
The problem for me was the availability. Also I have 305/30R19 and it isn't enough sidewall for me so 315/25 is even less. Plus I remember a Nitto, which are said to run narrower than others. Just wasn't worth it.