I've been running NGK 6097, but I'm tired of the short life of these. Sometimes they last a few thousand miles, other times they seem to be shot after a few hundred. Car is my daily driver BPU+...Car run at 1.2 bar, but often boosts to 1.4+ when it's cool out. I'm trying to decide whether I should run IK22 or IK24. Anyone with experience please chime in. Oh..and will these work OK with unleaded race fuel? Thanks!!