from my experience… the thermal value of the spark plug should be with higher boost and achievement a stage more coldly… security reserve with a FR5 LDC…. the combustion chamber of the 996 turbo engine is designed for a preferred eletrode position….this electrode is located more deeply in the combustion chamber. .advantage good burn….only with extreme poweroutputs can be deviated from this electrode position… my recommendation for long distance runs FR5 LDC otherwise FR6LDC…

for application from stock till 1,1 bar FR6 LDC....from 1,2 bar till 1,4 bar FR5 LDC.. with extreme power output over 1,4bar you should talk your tuner, he knows exactly what his tuning need....