Hello Guys,

I did lots of research in this forum regarding about spark plugs. I see lots of people didn't torque it right and mess up the engine. The torqe spec is 13 ft/lbs but some reccommend 18 ft/lbs which I think it's good.

I'm confused with the pre-gapped and gapped adjustment. I know most of the dealership sell spark plugs pre-gapped but how come we have to measure it and gapped it again?

1) Question: What's the gap for the S2000 ap1 / ap2? Is it 1.0 mm (.040") or is it 1.1 mm (.044")?

2) Question: Where can you get the measuring tools (feeler gauges or wire gauges) and how to use them? Pictures would be appreciate!

3) Question: For OEM spark plugs what's the part #? there should be an "S" at the end of the part right?

4) Question: Heat rating Numbers
<---------------------------->
2(hot) 11(cold)
what's the heat rating for OEM Spark Plugs? I think 7 but not sure? What's hot do and cold do?

5) Question: Preminum Platinum and Iridium Platinum? What's the difference?

Sorry for the long post. I couldn't understand everything

Thank You for all the help in advance!!