1.0 - 2.0 ?
 

On losi's web sight they show the 1.0 being 415.9mm wide and the 2.0 being 415.9mm wide but it says in the 2.0 write-up that all suspension arms are 15mm longer if that is so why does width stay the same.

I believe it means a 15mm longer wheelbase

The 1.0 uses different offset rims than the 2.0, longer arms but the overall width is the same.

if your thinking about converting to a 2.0. DO IT, it is a night and day difference in the two if you race