Maybe it has to do with the ply of tire. Most of the 17" tires I've been looking at are 8 ply instead of 6 ply. Maybe thats it????

 

Yeah maybe you are right about the PLY that would make sense..

The tread would explain it as well...

 

No, it would not, as the ply RATINGS have ZERO to do with the actual number of plies.

The LOAD RATING would make more of a difference....as that requires a thicker sidewall typically, so even though the 16" tire has more rubber to fill in than the same sized diameter 17" tire (The larger hole is air, which is lighter than rubber...so if all factors were the same, the 16" version is heavier than the 17" version).

I think if you do apples to apples, you'd see the 16" tires ARE heavier.

 

Well I think, apples to apples would be "tire weight" in which the 16" are lighter.


http://www.tirerack.com/tires/Spec.j...tination+M%2FT