I just hit 115 when I raced my brother, and had no issues what so ever. I was confused because the whistle sound didn't happen! I shifted from 4th at 106 not sure what the rpm was, but it was asking for the shift! Lol. Handled great throughout and no vibrations (except when I launched because I turnd off the traction control) I sometimes hit 90 on specific roads around here, because its easy to know where cops sit when you've lived in the same place for your entire life and like to open her up. South Jersey roads are good for that.Maybe it's just me,but why go 90 and for how long? Is it just to see if your xB can go 90? By the way, how does it handle,any vibrations,what RPMs are you upto? Just curious.