Could someone help me with Spark Plug types? I`m currently in Japan and HKS Spark Plugs are not so expensive over here, however I have the choice between 3 types, which are : 35i, 40i and 45i. What does that mean? Are HKS Spark Plugs recommended or shall I go for the Blitz or the much cheaper NGK ones? Or just keep my standard ones? Is there any noticable improvement in changing from std to HKS, Apexi or Blitz ones?

Thanks for your help,
Ramon

 

I use the NGK PFR7B's for my modded sti2 . These seem to do the buisness

 

Ok I understood now what 35i, 40i and 45i means, it seems to correspond to the heat ranges 7, 8 and 9.
Now which heat range is recommended for a lightly tuned MY99 Turbo?

Thanks,
Ramon

 

As standard NGK recommend PFR6B's , so the 7's should be ok .