DKL,
I know, I know ...
The UTQG is really a misnomer and mkting stuff from each company,
though it isn't clear that it's only within brands, not across brands,
based on the near anecdotal & very thin testing data.

I was going to paste the long winded version, with disclaimers, but
I felt the OP was not looking for a term paper and, more potential
confusion...If I were looking for potentially longer wearing tread, I
would cop the Michey Latitudes, but everyone's MMV!
Thanks for the clarification, though.
BR,mD

Tire Tech Information - Uniform Tire Quality Grade (UTQG) Standards