Ok, today I got the rest of the stuff from Tire Rack that I had ordered as part of my new, winter/wheels package. My telephone rep. set me up with a Gorilla bar, their reasonably-priced home use torque wrench, and also a thin wall socket. For the OEM lugs on my G37S wheels, he said I needed a 21mm socket. What I got in the box was a Gorilla 13/16 socket-close, but take a look at the photo, attached. The lug fits into the socket only partially and the seating is unstable. My McGuard key does not even fit at all. I am guessing the same will be true for the lugs that came with the Sport Edition wheels I ordered. So, what is the right socket size? This does not seem to be right. I tried the lugs on my old-fashioned four-way wrench, and they seat all the way to the base. Thanks.

 

I use 21mm as well for for our OEM. However 13/16 is actually a tighter fit. 20mm socket nor wrench simply does not exist in US tool market, unless you machine your own.

13/16 equals 20.6375mm. However if you use 13/16 there is a chance that the socket will get stuck on the lug nuts. Especially when torqued with impact gun. I recommend size 21mm even if they are slightly bigger. I never measured the lug nuts but they should be somewhere between 20.6375mm and 21mm. Closer to 21mm than 13/16.

Well regards to your 4 way wrench they are MADE IN JAPAN.

Try 21mm deep wall socket @ harborfreight they only cost less than $2

 

Thank you for your reply, I will try that. I tried the lugs last night that Tire Rack shipped with the Sport Ed. F10 wheels-the 13/16ths fits fine for those. So I will just have to get the 21mm for the others. Yes, I could see that I could not risk using the 13/16ths on the OEM, would be a mishap waiting to happen.

 

The lug nuts on a 2010 G37 are 21mm.