Why " 1 by" sill plates?

[banzaitoyota]

Why do most manufactured homes use a 1 x 4 or 1 x 6 sill plate when they make loud claims of their 2 x 4 or 2 x 6 Exterior wall construction? Why do they not overlap athe lower sheet of OSB/Plywood to the joist instead of installing the filler strip?

[rbonnie]

The 1x is a code compliant sill plate for this type of construction. The wall system is built "off line" and then brought to the assembly line and set down on the floor. Nothing in the way to obstruct the wall movement prior to nailing.