Tires: tire weights, utqg treadwear, cooper cs4

Question
Replacing tires on '06 Pont Torrent.  235/60R17.  A Cooper CS4 (780AA) weighs 33 pounds and Kumho Solus KR21 (680AB) weighs 28. Seems like quite a difference.  Would there be any link to tire quality? Better materials etc.  

Answer
Russ,

Unfortunately, weight - when everything else is kept constant - is not much indication of anything other than the amount of material used.

In this comparison, I'm sure some of the weight is in the tread to get the larger UTQG treadwear rating of the CS4.  But other than that, there may be many reasons why the Cooper tire weighs more, but it doesn't connect very well with anything in the performance arena.