I've got a decent tune for the Tomahawk GTS-R at 750pp. I have been trying to "dumb it down" to 700pp by doing various races in A-Spec, B-Spec and even practicing lap after lap at Sierra. I've noticed that most cars start to shed PP after around 300 or so miles. I have over 1,100 on my GTS-R, but it holds fast at 750pp and hasn't dropped at all yet. Has anyone else had this problem? Is this a VGT bug?