The way it was explained to me, from the old timer that got me into RV'ing (AKA Father-In-Law) was like this:
Small "truck tires" = motorhome (doesn't matter how many tires you have either or Tag vs. No Tag)
Large "bus tires" = Coach
Prevost style "Coach" = "LUXURY" Coach, or, as some of you have put it, "Motorcoach"
To him NOT understanding was his way of starting the conversation about what we do as RVers...and HOW he got so many people "involved" (read as hooked) into RV'ing.
The reason I try to keep his "logic" (since he passed away) is because it provides a "path" to the Prevost: Motorhome - Coach - PREVOST!!!!
Yeah Baby! LOL