The light problem is caused by "LEVC.bgl" in "AKESOFT VALENCIA-X FSX\scenery", that control the rwy light. Delete it and you have fixed the performance issue on night... and the rwy light too :/ I've tried to add the light with AFCAD (and similar program) but they can be visible only on the ground level, there is a layout problem with the bgl that control the rwy surface. The taxi light doesn't cause any fps drop.If the authors of the scenery shows up maybe they can do something about!