"Usable" floorplan area sounds about right over all. Just depends on what the manufacturer includes in the "usable" area. In '92, Winnebago called our Adventurer a 32' model. But measuring bumper-to-bumper with a tape measure, it comes out to nearly 40'. The 8' or so in question appears to be mostly the front bumper to the back of the "cab" area, which is a fair stretch, since the front is raked back a bit and there's a fair bit of leg room ahead of the cab area seats, plus more overhang for the front end. If I were to guess, they used the trucking industry "BBC" (Bumper to Back-of-Cab) measurement and subtracted it to leave the rest of the chassis as the living area measurement. Nice to get some "free" length, but we quote it as a 40-footer for campgrounds, since that gives a fairer idea of how much rig to fit a site.
Eric & Holly + 2 kitties from New Hampshire
1992 Winnebago Adventurer 32'