the wheel offset changes the width on the truck. SOme trucks(Losi,Jammin) used 1/2 offset wheels to reach the correct width for their trucks. Kyosho,Mugen and a few others used standard or 0 offset wheels plus hub extenders to reach the ideal width. Once the Losi comes out the Jammin will be the only truck left using 1/2 offset wheels. People have tires from the 8ight T 1.0 that they would like to use when the new truck comes out but they wil not be able to with the new truck IF it uses longer arms.