Spark plugs...

Originally Posted by Motion Lab

No, the GT-R uses a DILKAR8A8 plug which has a smaller gap and a different grounding strap design.

As for the original question I would stick with the OEM heat range. The VQ37HR is already somewhat prone to detonation. 11:1CR on pump gas makes it difficult enough to pick up power, don't put yourself CLOSER to detonation with the hotter plug. By storing less heat in the plug your tuner might be able to squeeze a little more power out before he finds the limit of where the engine is happy.

Hotter plugs will make more power with the right fuel, but I wouldn't run a hotter plug without e85 or higher octane race fuel not just plain ol' pump gas.

Just my opinion!

Thanks,
Alex Goodwin
AlexG@motionlabtuning.com