Tire weight ratings

[DBoyd]

Why are the tire weight ratings always less when used as duals instead of as a single tire?

 

[MJawsman]

The close proximity of the other tire forces a lighter rating due to heat build up. At least that's what I was told. Seems to make sense, but then again.....

 

[DBoyd]

Thanks Mjawsman

I was told it had to do with the crown of the road affecting the load on each tire in the dual set and I was wondering if anyone else had heard that. I dunno if I buy that or not.