Welcome to GasSavers!
First off post up Garage entries for your vehicles and a Gas Log if you have the info . It will help you keep track of whats working with your efforts . It will help us learn too .
As far as the motorhome ...park it , pack a tent in the Saturn I just improved the FE a bunch (or better still rent a cabin or motel room iffn you are into more luxurious surroundings) ...sorry I had to