When the term was first used (GM Autonomy 2002) it was a concept for a complete powertrain below the hubline. Ya, it's pretty similar to body-on-frame, although

When the term was first used (GM Autonomy 2002) it was a concept for a complete powertrain below the hubline. Ya, it's pretty similar to body-on-frame, although it suggests much more freedom in body design since nearly all of the power train is below the hubs.