Lug size question.

So I have ridge grapplers that I put on my stock 20 inch wheels. When these wear out I'll upgrade to 18s, but I digress. The lugs on my RGs always looked shallow to me but it still performs great off road. Well the other day I saw some massive RGs on a 17 wheel and the lugs were insanely deep. Was I wrong to think that the lug size for a tire model stays consistent for all tire sizes for that model?

 

It can be different, even within the same wheel size, for instance the 295/65r20 RG has a tread depth of 16.4 and the 35x12.5r20 has a tread depth of 18.3

 

P-rated will be around 13-14 32nds deep, LT are usually 16-18 32nds. That is probably the difference you saw

 

It was alot deeper than a few 32nds. I wish I would've taken a picture.