So I'm in need of purchasing some spark plugs and with the rest of my order I'm getting some NGK Iridium's off of enjuku.
They show the different heat ranges for different amounts of boost you're running here's the list if you don't know what I mean.
- Heat Range 6 for stock turbo 8-12psi
- Heat Range 7 for upgraded turbo 13-15psi
- Heat Range 8 for upgraded turbo 16-20psi
- Heat Range 9 for upgraded turbo 21+psi
Now come's my question.. I'm planning to run 12psi for low boost which is what I'll be at most of the time being as it's my dd but I also was planning to run 18 psi for my high boost so really don't have any idea which heat range to get. Any info is appreciated.