Socket size for sparks plug?

No way! I though he was referring to me!

 

I just found this thread, while looking to make sure which tools to pick up. New wrinkle. Denso looks to have updated the website from 14.2mm to now say: 9/16" (14mm). The world is chaos.

 

14 mm is slightly snugger. I've used 9/16"; thought that was the official size, but considering it's Japan probably 14 is the way to go if you can find it in a spark plug socket (rubber insert to grip the plug).

 

I was excited receiving the 3/8 drive GearWrench 5 pc magnetic spark plug socket set with 9/16 & 5/8 sockets that NutzAboutBolts recommends. And it seems that 9/16 and 14mm are considered swappable but I am going to get a dedicated 14mm instead. I won't be removing the spark plugs all the time and risk rounding the corners but 14mm is the proper recommendation for a spark plug job.