I know this was brought up briefly once with no conclusion, but I'm approaching 60k and the service manual says I need to change the plugs, even though they're the same as the base model. Has anyone with an IPL or tune checked their plugs at this mileage? Would the service manual really specify this for a legit reason? Denso site lists 80k-100k and I've read some people changed them at 75k.

2012 IPL Coupe 6MT w/ ECUtek tune

 

Take them out and inspect them. If they look good put them back and don’t forget to torque them down. If they are darker in the end then replace them. Their is videos on YouTube as to how to determine if your sparks and in good condition or not. I changed mine out 90k miles and it was light brown could have went more but I just changed it either way. I drive a G37xS.

 

105k miles.